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 fetchmail(1)                     fetchmail                     fetchmail(1)
 fetchmail reference manual                       fetchmail reference manual

                              fetchmail 6.3.26



 NAME
      fetchmail - fetch mail from a POP, IMAP, ETRN, or ODMR-capable server


 SYNOPSIS
      fetchmail [option...] [mailserver...]
      fetchmailconf


 DESCRIPTION
      fetchmail is a mail-retrieval and forwarding utility; it fetches mail
      from remote mailservers and forwards it to your local (client)
      machine's delivery system.  You can then handle the retrieved mail
      using normal mail user agents such as mutt(1), elm(1) or Mail(1).  The
      fetchmail utility can be run in a daemon mode to repeatedly poll one
      or more systems at a specified interval.

      The fetchmail program can gather mail from servers supporting any of
      the common mail-retrieval protocols: POP2 (legacy, to be removed from
      future release), POP3, IMAP2bis, IMAP4, and IMAP4rev1.  It can also
      use the ESMTP ETRN extension and ODMR.  (The RFCs describing all these
      protocols are listed at the end of this manual page.)

      While fetchmail is primarily intended to be used over on-demand TCP/IP
      links (such as SLIP or PPP connections), it may also be useful as a
      message transfer agent for sites which refuse for security reasons to
      permit (sender-initiated) SMTP transactions with sendmail.


    SUPPORT, TROUBLESHOOTING
      For troubleshooting, tracing and debugging, you need to increase
      fetchmail's verbosity to actually see what happens. To do that, please
      run both of the two following commands, adding all of the options
      you'd normally use.



           env LC_ALL=C fetchmail -V -v --nodetach --nosyslog

           (This command line prints in English how fetchmail understands
           your configuration.)



           env LC_ALL=C fetchmail -vvv  --nodetach --nosyslog

           (This command line actually runs fetchmail with verbose English
           output.)




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      Also see

      You can omit the LC_ALL=C part above if you want output in the local
      language (if supported). However if you are posting to mailing lists,
      please leave it in. The maintainers do not necessarily understand your
      language, please use English.




    CONCEPTS
      If fetchmail is used with a POP or an IMAP server (but not with ETRN
      or ODMR), it has two fundamental modes of operation for each user
      account from which it retrieves mail: singledrop- and multidrop-mode.

      In singledrop-mode,
           fetchmail assumes that all messages in the user's account
           (mailbox) are intended for a single recipient.  The identity of
           the recipient will either default to the local user currently
           executing fetchmail, or will need to be explicitly specified in
           the configuration file.

           fetchmail uses singledrop-mode when the fetchmailrc configuration
           contains at most a single local user specification for a given
           server account.

      In multidrop-mode,
           fetchmail assumes that the mail server account actually contains
           mail intended for any number of different recipients.  Therefore,
           fetchmail must attempt to deduce the proper "envelope recipient"
           from the mail headers of each message.  In this mode of
           operation, fetchmail almost resembles a mail transfer agent
           (MTA).

           Note that neither the POP nor IMAP protocols were intended for
           use in this fashion, and hence envelope information is often not
           directly available.  The ISP must stores the envelope information
           in some message header and. The ISP must also store one copy of
           the message per recipient. If either of the conditions is not
           fulfilled, this process is unreliable, because fetchmail must
           then resort to guessing the true envelope recipient(s) of a
           message. This usually fails for mailing list messages and Bcc:d
           mail, or mail for multiple recipients in your domain.

           fetchmail uses multidrop-mode when more than one local user
           and/or a wildcard is specified for a particular server account in
           the configuration file.

      In ETRN and ODMR modes,



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           these considerations do not apply, as these protocols are based
           on SMTP, which provides explicit envelope recipient information.
           These protocols always support multiple recipients.

      As each message is retrieved, fetchmail normally delivers it via SMTP
      to port 25 on the machine it is running on (localhost), just as though
      it were being passed in over a normal TCP/IP link.  fetchmail provides
      the SMTP server with an envelope recipient derived in the manner
      described previously.  The mail will then be delivered according to
      your MTA's rules (the Mail Transfer Agent is usually sendmail(8),
      exim(8), or postfix(8)).  Invoking your system's MDA (Mail Delivery
      Agent) is the duty of your MTA.  All the delivery-control mechanisms
      (such as .forward files) normally available through your system MTA
      and local delivery agents will therefore be applied as usual.

      If your fetchmail configuration sets a local MDA (see the --mda
      option), it will be used directly instead of talking SMTP to port 25.

      If the program fetchmailconf is available, it will assist you in
      setting up and editing a fetchmailrc configuration.  It runs under the
      X window system and requires that the language Python and the Tk
      toolkit (with Python bindings) be present on your system.  If you are
      first setting up fetchmail for single-user mode, it is recommended
      that you use Novice mode.  Expert mode provides complete control of
      fetchmail configuration, including the multidrop features.  In either
      case, the 'Autoprobe' button will tell you the most capable protocol a
      given mailserver supports, and warn you of potential problems with
      that server.


 GENERAL OPERATION
      The behavior of fetchmail is controlled by command-line options and a
      run control file, ~/.fetchmailrc, the syntax of which we describe in a
      later section (this file is what the fetchmailconf program edits).
      Command-line options override ~/.fetchmailrc declarations.

      Each server name that you specify following the options on the command
      line will be queried.  If you don't specify any servers on the command
      line, each 'poll' entry in your ~/.fetchmailrc file will be queried.

      To facilitate the use of fetchmail in scripts and pipelines, it
      returns an appropriate exit code upon termination -- see EXIT CODES
      below.

      The following options modify the behavior of fetchmail.  It is seldom
      necessary to specify any of these once you have a working .fetchmailrc
      file set up.

      Almost all options have a corresponding keyword which can be used to



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      declare them in a .fetchmailrc file.

      Some special options are not covered here, but are documented instead
      in sections on AUTHENTICATION and DAEMON MODE which follow.

    General Options
      -V | --version
           Displays the version information for your copy of fetchmail.  No
           mail fetch is performed.  Instead, for each server specified, all
           the option information that would be computed if fetchmail were
           connecting to that server is displayed.  Any non-printables in
           passwords or other string names are shown as backslashed C-like
           escape sequences.  This option is useful for verifying that your
           options are set the way you want them.

      -c | --check
           Return a status code to indicate whether there is mail waiting,
           without actually fetching or deleting mail (see EXIT CODES
           below).  This option turns off daemon mode (in which it would be
           useless).  It doesn't play well with queries to multiple sites,
           and doesn't work with ETRN or ODMR.  It will return a false
           positive if you leave read but undeleted mail in your server
           mailbox and your fetch protocol can't tell kept messages from new
           ones.  This means it will work with IMAP, not work with POP2, and
           may occasionally flake out under POP3.

      -s | --silent
           Silent mode.  Suppresses all progress/status messages that are
           normally echoed to standard output during a fetch (but does not
           suppress actual error messages).  The --verbose option overrides
           this.

      -v | --verbose
           Verbose mode.  All control messages passed between fetchmail and
           the mailserver are echoed to stdout.  Overrides --silent.
           Doubling this option (-v -v) causes extra diagnostic information
           to be printed.

      --nosoftbounce
           (since v6.3.10, Keyword: set no softbounce, since v6.3.10)
           Hard bounce mode. All permanent delivery errors cause messages to
           be deleted from the upstream server, see "no softbounce" below.

      --softbounce
           (since v6.3.10, Keyword: set softbounce, since v6.3.10)
           Soft bounce mode. All permanent delivery errors cause messages to
           be left on the upstream server if the protocol supports that.
           This option is on by default and will be changed to hard bounce
           mode in the next fetchmail release.



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    Disposal Options
      -a | --all | (since v6.3.3)
           (Keyword: fetchall, since v3.0)
           Retrieve both old (seen) and new messages from the mailserver.
           The default is to fetch only messages the server has not marked
           seen.  Under POP3, this option also forces the use of RETR rather
           than TOP.  Note that POP2 retrieval behaves as though --all is
           always on (see RETRIEVAL FAILURE MODES below) and this option
           does not work with ETRN or ODMR.  While the -a and --all
           command-line and fetchall rcfile options have been supported for
           a long time, the --fetchall command-line option was added in
           v6.3.3.

      -k | --keep
           (Keyword: keep)
           Keep retrieved messages on the remote mailserver.  Normally,
           messages are deleted from the folder on the mailserver after they
           have been retrieved.  Specifying the keep option causes retrieved
           messages to remain in your folder on the mailserver.  This option
           does not work with ETRN or ODMR. If used with POP3, it is
           recommended to also specify the --uidl option or uidl keyword.

      -K | --nokeep
           (Keyword: nokeep)
           Delete retrieved messages from the remote mailserver.  This
           option forces retrieved mail to be deleted.  It may be useful if
           you have specified a default of keep in your .fetchmailrc.  This
           option is forced on with ETRN and ODMR.

      -F | --flush
           (Keyword: flush)
           POP3/IMAP only.  This is a dangerous option and can cause mail
           loss when used improperly. It deletes old (seen) messages from
           the mailserver before retrieving new messages.  Warning: This can
           cause mail loss if you check your mail with other clients than
           fetchmail, and cause fetchmail to delete a message it had never
           fetched before.  It can also cause mail loss if the mail server
           marks the message seen after retrieval (IMAP2 servers). You
           should probably not use this option in your configuration file.
           If you use it with POP3, you must use the 'uidl' option. What you
           probably want is the default setting: if you don't specify '-k',
           then fetchmail will automatically delete messages after
           successful delivery.

      --limitflush
           POP3/IMAP only, since version 6.3.0.  Delete oversized messages
           from the mailserver before retrieving new messages. The size
           limit should be separately specified with the --limit option.
           This option does not work with ETRN or ODMR.



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    Protocol and Query Options
      -p <proto> | --proto <proto> |
           (Keyword: proto[col])
           Specify the protocol to use when communicating with the remote
           mailserver.  If no protocol is specified, the default is AUTO.
           proto may be one of the following:

           AUTO Tries IMAP, POP3, and POP2 (skipping any of these for which
                support has not been compiled in).

           POP2 Post Office Protocol 2 (legacy, to be removed from future
                release)

           POP3 Post Office Protocol 3

           APOP Use POP3 with old-fashioned MD5-challenge authentication.
                Considered not resistant to man-in-the-middle attacks.

           RPOP Use POP3 with RPOP authentication.

           KPOP Use POP3 with Kerberos V4 authentication on port 1109.

           SDPS Use POP3 with Demon Internet's SDPS extensions.

           IMAP IMAP2bis, IMAP4, or IMAP4rev1 (fetchmail automatically
                detects their capabilities).

           ETRN Use the ESMTP ETRN option.

           ODMR Use the the On-Demand Mail Relay ESMTP profile.

      All these alternatives work in basically the same way (communicating
      with standard server daemons to fetch mail already delivered to a
      mailbox on the server) except ETRN and ODMR.  The ETRN mode allows you
      to ask a compliant ESMTP server (such as BSD sendmail at release 8.8.0
      or higher) to immediately open a sender-SMTP connection to your client
      machine and begin forwarding any items addressed to your client
      machine in the server's queue of undelivered mail.   The ODMR mode
      requires an ODMR-capable server and works similarly to ETRN, except
      that it does not require the client machine to have a static DNS.

      -U | --uidl
           (Keyword: uidl)
           Force UIDL use (effective only with POP3).  Force client-side
           tracking of 'newness' of messages (UIDL stands for "unique ID
           listing" and is described in RFC1939).  Use with 'keep' to use a
           mailbox as a baby news drop for a group of users. The fact that
           seen messages are skipped is logged, unless error logging is done
           through syslog while running in daemon mode.  Note that fetchmail



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           may automatically enable this option depending on upstream server
           capabilities.  Note also that this option may be removed and
           forced enabled in a future fetchmail version. See also: --idfile.

      --idle (since 6.3.3)
           (Keyword: idle, since before 6.0.0)
           Enable IDLE use (effective only with IMAP). Note that this works
           with only one folder at a given time.  While the idle rcfile
           keyword had been supported for a long time, the --idle command-
           line option was added in version 6.3.3. IDLE use means that
           fetchmail tells the IMAP server to send notice of new messages,
           so they can be retrieved sooner than would be possible with
           regular polls.

      -P <portnumber> | --service <servicename>
           (Keyword: service) Since version 6.3.0.
           The service option permits you to specify a service name to
           connect to.  You can specify a decimal port number here, if your
           services database lacks the required service-port assignments.
           See the FAQ item R12 and the --ssl documentation for details.
           This replaces the older --port option.

      --port <portnumber>
           (Keyword: port)
           Obsolete version of --service that does not take service names.
           Note: this option may be removed from a future version.

      --principal <principal>
           (Keyword: principal)
           The principal option permits you to specify a service principal
           for mutual authentication.  This is applicable to POP3 or IMAP
           with Kerberos 4 authentication only.  It does not apply to
           Kerberos 5 or GSSAPI.  This option may be removed in a future
           fetchmail version.

      -t <seconds> | --timeout <seconds>
           (Keyword: timeout)
           The timeout option allows you to set a server-nonresponse timeout
           in seconds.  If a mailserver does not send a greeting message or
           respond to commands for the given number of seconds, fetchmail
           will drop the connection to it.  Without such a timeout fetchmail
           might hang until the TCP connection times out, trying to fetch
           mail from a down host, which may be very long.  This would be
           particularly annoying for a fetchmail running in the background.
           There is a default timeout which fetchmail~-V will report.  If a
           given connection receives too many timeouts in succession,
           fetchmail will consider it wedged and stop retrying.  The calling
           user will be notified by email if this happens.




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           Beginning with fetchmail 6.3.10, the SMTP client uses the
           recommended minimum timeouts from RFC-5321 while waiting for the
           SMTP/LMTP server it is talking to.  You can raise the timeouts
           even more, but you cannot shorten them. This is to avoid a
           painful situation where fetchmail has been configured with a
           short timeout (a minute or less), ships a long message (many
           MBytes) to the local MTA, which then takes longer than timeout to
           respond "OK", which it eventually will; that would mean the mail
           gets delivered properly, but fetchmail cannot notice it and will
           thus refetch this big message over and over again.

      --plugin <command>
           (Keyword: plugin)
           The plugin option allows you to use an external program to
           establish the TCP connection.  This is useful if you want to use
           ssh, or need some special firewalling setup.  The program will be
           looked up in $PATH and can optionally be passed the hostname and
           port as arguments using "%h" and "%p" respectively (note that the
           interpolation logic is rather primitive, and these tokens must be
           bounded by whitespace or beginning of string or end of string).
           Fetchmail will write to the plugin's stdin and read from the
           plugin's stdout.

      --plugout <command>
           (Keyword: plugout)
           Identical to the plugin option above, but this one is used for
           the SMTP connections.

      -r <name> | --folder <name>
           (Keyword: folder[s])
           Causes a specified non-default mail folder on the mailserver (or
           comma-separated list of folders) to be retrieved.  The syntax of
           the folder name is server-dependent.  This option is not
           available under POP3, ETRN, or ODMR.

      --tracepolls
           (Keyword: tracepolls)
           Tell fetchmail to poll trace information in the form 'polling
           account %s' and 'folder %s' to the Received line it generates,
           where the %s parts are replaced by the user's remote name, the
           poll label, and the folder (mailbox) where available (the
           Received header also normally includes the server's true name).
           This can be used to facilitate mail filtering based on the
           account it is being received from. The folder information is
           written only since version 6.3.4.

      --ssl
           (Keyword: ssl)
           Causes the connection to the mail server to be encrypted via SSL.



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           Connect to the server using the specified base protocol over a
           connection secured by SSL. This option defeats opportunistic
           starttls negotiation. It is highly recommended to use --sslproto
           'SSL3' --sslcertck to validate the certificates presented by the
           server and defeat the obsolete SSLv2 negotiation. More
           information is available in the README.SSL file that ships with
           fetchmail.

           Note that fetchmail may still try to negotiate SSL through
           starttls even if this option is omitted. You can use the
           --sslproto option to defeat this behavior or tell fetchmail to
           negotiate a particular SSL protocol.

           If no port is specified, the connection is attempted to the well
           known port of the SSL version of the base protocol.  This is
           generally a different port than the port used by the base
           protocol.  For IMAP, this is port 143 for the clear protocol and
           port 993 for the SSL secured protocol, for POP3, it is port 110
           for the clear text and port 995 for the encrypted variant.

           If your system lacks the corresponding entries from
           /etc/services, see the --service option and specify the numeric
           port number as given in the previous paragraph (unless your ISP
           had directed you to different ports, which is uncommon however).

      --sslcert <name>
           (Keyword: sslcert)
           For certificate-based client authentication.  Some SSL encrypted
           servers require client side keys and certificates for
           authentication.  In most cases, this is optional.  This specifies
           the location of the public key certificate to be presented to the
           server at the time the SSL session is established.  It is not
           required (but may be provided) if the server does not require it.
           It may be the same file as the private key (combined key and
           certificate file) but this is not recommended. Also see --sslkey
           below.

           NOTE: If you use client authentication, the user name is fetched
           from the certificate's CommonName and overrides the name set with
           --user.

      --sslkey <name>
           (Keyword: sslkey)
           Specifies the file name of the client side private SSL key.  Some
           SSL encrypted servers require client side keys and certificates
           for authentication.  In most cases, this is optional.  This
           specifies the location of the private key used to sign
           transactions with the server at the time the SSL session is
           established.  It is not required (but may be provided) if the



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           server does not require it. It may be the same file as the public
           key (combined key and certificate file) but this is not
           recommended.

           If a password is required to unlock the key, it will be prompted
           for at the time just prior to establishing the session to the
           server.  This can cause some complications in daemon mode.

           Also see --sslcert above.

      --sslproto <name>
           (Keyword: sslproto)
           Forces an SSL/TLS protocol. Possible values are '', 'SSL2' (not
           supported on all systems), 'SSL23', (use of these two values is
           discouraged and should only be used as a last resort) 'SSL3', and
           'TLS1'.  The default behaviour if this option is unset is: for
           connections without --ssl, use 'TLS1' so that fetchmail will
           opportunistically try STARTTLS negotiation with TLS1. You can
           configure this option explicitly if the default handshake (TLS1
           if --ssl is not used) does not work for your server.

           Use this option with 'TLS1' value to enforce a STARTTLS
           connection. In this mode, it is highly recommended to also use
           --sslcertck (see below).  Note that this will then cause
           fetchmail v6.3.19 to force STARTTLS negotiation even if it is not
           advertised by the server.

           To defeat opportunistic TLSv1 negotiation when the server
           advertises STARTTLS or STLS, and use a cleartext connection use
           ''.  This option, even if the argument is the empty string, will
           also suppress the diagnostic 'SERVER: opportunistic upgrade to
           TLS.' message in verbose mode. The default is to try appropriate
           protocols depending on context.

      --sslcertck
           (Keyword: sslcertck)
           Causes fetchmail to strictly check the server certificate against
           a set of local trusted certificates (see the sslcertfile and
           sslcertpath options). If the server certificate cannot be
           obtained or is not signed by one of the trusted ones (directly or
           indirectly), the SSL connection will fail, regardless of the
           sslfingerprint option.

           Note that CRL (certificate revocation lists) are only supported
           in OpenSSL 0.9.7 and newer! Your system clock should also be
           reasonably accurate when using this option.

           Note that this optional behavior may become default behavior in
           future fetchmail versions.



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      --sslcertfile <file>
           (Keyword: sslcertfile, since v6.3.17)
           Sets the file fetchmail uses to look up local certificates.  The
           default is empty.  This can be given in addition to --sslcertpath
           below, and certificates specified in --sslcertfile will be
           processed before those in --sslcertpath.  The option can be used
           in addition to --sslcertpath.

           The file is a text file. It contains the concatenation of trusted
           CA certificates in PEM format.

           Note that using this option will suppress loading the default SSL
           trusted CA certificates file unless you set the environment
           variable FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS to a non-empty
           value.

      --sslcertpath <directory>
           (Keyword: sslcertpath)
           Sets the directory fetchmail uses to look up local certificates.
           The default is your OpenSSL default directory. The directory must
           be hashed the way OpenSSL expects it - every time you add or
           modify a certificate in the directory, you need to use the
           c_rehash tool (which comes with OpenSSL in the tools/
           subdirectory). Also, after OpenSSL upgrades, you may need to run
           c_rehash; particularly when upgrading from 0.9.X to 1.0.0.

           This can be given in addition to --sslcertfile above, which see
           for precedence rules.

           Note that using this option will suppress adding the default SSL
           trusted CA certificates directory unless you set the environment
           variable FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS to a non-empty
           value.

      --sslcommonname <common name>
           (Keyword: sslcommonname; since v6.3.9)
           Use of this option is discouraged. Before using it, contact the
           administrator of your upstream server and ask for a proper SSL
           certificate to be used. If that cannot be attained, this option
           can be used to specify the name (CommonName) that fetchmail
           expects on the server certificate.  A correctly configured server
           will have this set to the hostname by which it is reached, and by
           default fetchmail will expect as much. Use this option when the
           CommonName is set to some other value, to avoid the "Server
           CommonName mismatch" warning, and only if the upstream server
           can't be made to use proper certificates.

      --sslfingerprint <fingerprint>
           (Keyword: sslfingerprint)



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           Specify the fingerprint of the server key (an MD5 hash of the
           key) in hexadecimal notation with colons separating groups of two
           digits. The letter hex digits must be in upper case. This is the
           format that fetchmail uses to report the fingerprint when an SSL
           connection is established. When this is specified, fetchmail will
           compare the server key fingerprint with the given one, and the
           connection will fail if they do not match, regardless of the
           sslcertck setting. The connection will also fail if fetchmail
           cannot obtain an SSL certificate from the server.  This can be
           used to prevent man-in-the-middle attacks, but the finger print
           from the server needs to be obtained or verified over a secure
           channel, and certainly not over the same Internet connection that
           fetchmail would use.

           Using this option will prevent printing certificate verification
           errors as long as --sslcertck is unset.

           To obtain the fingerprint of a certificate stored in the file
           cert.pem, try:

                openssl x509 -in cert.pem -noout -md5 -fingerprint

           For details, see x509(1ssl).

    Delivery Control Options
      -S <hosts> | --smtphost <hosts>
           (Keyword: smtp[host])
           Specify a hunt list of hosts to forward mail to (one or more
           hostnames, comma-separated). Hosts are tried in list order; the
           first one that is up becomes the forwarding target for the
           current run.  If this option is not specified, 'localhost' is
           used as the default.  Each hostname may have a port number
           following the host name.  The port number is separated from the
           host name by a slash; the default port is "smtp".  If you specify
           an absolute path name (beginning with a /), it will be
           interpreted as the name of a UNIX socket accepting LMTP
           connections (such as is supported by the Cyrus IMAP daemon)
           Example:

                --smtphost server1,server2/2525,server3,/var/imap/socket/lmtp

           This option can be used with ODMR, and will make fetchmail a
           relay between the ODMR server and SMTP or LMTP receiver.

      --fetchdomains <hosts>
           (Keyword: fetchdomains)
           In ETRN or ODMR mode, this option specifies the list of domains
           the server should ship mail for once the connection is turned
           around.  The default is the FQDN of the machine running



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           fetchmail.

      -D <domain> | --smtpaddress <domain>
           (Keyword: smtpaddress)
           Specify the domain to be appended to addresses in RCPT TO lines
           shipped to SMTP. When this is not specified, the name of the SMTP
           server (as specified by --smtphost) is used for SMTP/LMTP and
           'localhost' is used for UNIX socket/BSMTP.

      --smtpname <user@domain>
           (Keyword: smtpname)
           Specify the domain and user to be put in RCPT TO lines shipped to
           SMTP.  The default user is the current local user.

      -Z <nnn> | --antispam <nnn[, nnn]...>
           (Keyword: antispam)
           Specifies the list of numeric SMTP errors that are to be
           interpreted as a spam-block response from the listener.  A value
           of -1 disables this option.  For the command-line option, the
           list values should be comma-separated.

      -m <command> | --mda <command>
           (Keyword: mda)
           This option lets fetchmail use a Message or Local Delivery Agent
           (MDA or LDA) directly, rather than forward via SMTP or LMTP.

           To avoid losing mail, use this option only with MDAs like
           maildrop or MTAs like sendmail that exit with a nonzero status on
           disk-full and other delivery errors; the nonzero status tells
           fetchmail that delivery failed and prevents the message from
           being deleted on the server.

           If fetchmail is running as root, it sets its user id while
           delivering mail through an MDA as follows:  First, the
           FETCHMAILUSER, LOGNAME, and USER environment variables are
           checked in this order. The value of the first variable from his
           list that is defined (even if it is empty!) is looked up in the
           system user database. If none of the variables is defined,
           fetchmail will use the real user id it was started with. If one
           of the variables was defined, but the user stated there isn't
           found, fetchmail continues running as root, without checking
           remaining variables on the list.  Practically, this means that if
           you run fetchmail as root (not recommended), it is most useful to
           define the FETCHMAILUSER environment variable to set the user
           that the MDA should run as. Some MDAs (such as maildrop) are
           designed to be setuid root and setuid to the recipient's user id,
           so you don't lose functionality this way even when running
           fetchmail as unprivileged user.  Check the MDA's manual for
           details.



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           Some possible MDAs are "/usr/sbin/sendmail -i -f %F -- %T" (Note:
           some several older or vendor sendmail versions mistake -- for an
           address, rather than an indicator to mark the end of the option
           arguments), "/usr/bin/deliver" and "/usr/bin/maildrop -d %T".
           Local delivery addresses will be inserted into the MDA command
           wherever you place a %T; the mail message's From address will be
           inserted where you place an %F.

           Do NOT enclose the %F or %T string in single quotes!  For both %T
           and %F, fetchmail encloses the addresses in single quotes ('),
           after removing any single quotes they may contain, before the MDA
           command is passed to the shell.

           Do NOT use an MDA invocation that dispatches on the contents of
           To/Cc/Bcc, like "sendmail -i -t" or "qmail-inject", it will
           create mail loops and bring the just wrath of many postmasters
           down upon your head.  This is one of the most frequent
           configuration errors!

           Also, do not try to combine multidrop mode with an MDA such as
           maildrop that can only accept one address, unless your upstream
           stores one copy of the message per recipient and transports the
           envelope recipient in a header; you will lose mail.

           The well-known procmail(1) package is very hard to configure
           properly, it has a very nasty "fall through to the next rule"
           behavior on delivery errors (even temporary ones, such as out of
           disk space if another user's mail daemon copies the mailbox
           around to purge old messages), so your mail will end up in the
           wrong mailbox sooner or later. The proper procmail configuration
           is outside the scope of this document. Using maildrop(1) is
           usually much easier, and many users find the filter syntax used
           by maildrop easier to understand.

           Finally, we strongly advise that you do not use qmail-inject.
           The command line interface is non-standard without providing
           benefits for typical use, and fetchmail makes no attempts to
           accommodate qmail-inject's deviations from the standard. Some of
           qmail-inject's command-line and environment options are actually
           dangerous and can cause broken threads, non-detected duplicate
           messages and forwarding loops.


      --lmtp
           (Keyword: lmtp)
           Cause delivery via LMTP (Local Mail Transfer Protocol).  A
           service host and port must be explicitly specified on each host
           in the smtphost hunt list (see above) if this option is selected;
           the default port 25 will (in accordance with RFC 2033) not be



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           accepted.

      --bsmtp <filename>
           (Keyword: bsmtp)
           Append fetched mail to a BSMTP file.  This simply contains the
           SMTP commands that would normally be generated by fetchmail when
           passing mail to an SMTP listener daemon.

           An argument of '-' causes the SMTP batch to be written to
           standard output, which is of limited use: this only makes sense
           for debugging, because fetchmail's regular output is interspersed
           on the same channel, so this isn't suitable for mail delivery.
           This special mode may be removed in a later release.

           Note that fetchmail's reconstruction of MAIL FROM and RCPT TO
           lines is not guaranteed correct; the caveats discussed under THE
           USE AND ABUSE OF MULTIDROP MAILBOXES below apply.  This mode has
           precedence before --mda and SMTP/LMTP.

      --bad-header {reject|accept}
           (Keyword: bad-header; since v6.3.15)
           Specify how fetchmail is supposed to treat messages with bad
           headers, i. e. headers with bad syntax. Traditionally, fetchmail
           has rejected such messages, but some distributors modified
           fetchmail to accept them. You can now configure fetchmail's
           behaviour per server.


    Resource Limit Control Options
      -l <maxbytes> | --limit <maxbytes>
           (Keyword: limit)
           Takes a maximum octet size argument, where 0 is the default and
           also the special value designating "no limit".  If nonzero,
           messages larger than this size will not be fetched and will be
           left on the server (in foreground sessions, the progress messages
           will note that they are "oversized").  If the fetch protocol
           permits (in particular, under IMAP or POP3 without the fetchall
           option) the message will not be marked seen.

           An explicit --limit of 0 overrides any limits set in your run
           control file. This option is intended for those needing to
           strictly control fetch time due to expensive and variable phone
           rates.

           Combined with --limitflush, it can be used to delete oversized
           messages waiting on a server.  In daemon mode, oversize
           notifications are mailed to the calling user (see the --warnings
           option). This option does not work with ETRN or ODMR.




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      -w <interval> | --warnings <interval>
           (Keyword: warnings)
           Takes an interval in seconds.  When you call fetchmail with a
           'limit' option in daemon mode, this controls the interval at
           which warnings about oversized messages are mailed to the calling
           user (or the user specified by the 'postmaster' option).  One
           such notification is always mailed at the end of the the first
           poll that the oversized message is detected.  Thereafter, re-
           notification is suppressed until after the warning interval
           elapses (it will take place at the end of the first following
           poll).

      -b <count> | --batchlimit <count>
           (Keyword: batchlimit)
           Specify the maximum number of messages that will be shipped to an
           SMTP listener before the connection is deliberately torn down and
           rebuilt (defaults to 0, meaning no limit).  An explicit
           --batchlimit of 0 overrides any limits set in your run control
           file.  While sendmail(8) normally initiates delivery of a message
           immediately after receiving the message terminator, some SMTP
           listeners are not so prompt.  MTAs like smail(8) may wait till
           the delivery socket is shut down to deliver.  This may produce
           annoying delays when fetchmail is processing very large batches.
           Setting the batch limit to some nonzero size will prevent these
           delays.  This option does not work with ETRN or ODMR.

      -B <number> | --fetchlimit <number>
           (Keyword: fetchlimit)
           Limit the number of messages accepted from a given server in a
           single poll.  By default there is no limit. An explicit
           --fetchlimit of 0 overrides any limits set in your run control
           file.  This option does not work with ETRN or ODMR.

      --fetchsizelimit <number>
           (Keyword: fetchsizelimit)
           Limit the number of sizes of messages accepted from a given
           server in a single transaction.  This option is useful in
           reducing the delay in downloading the first mail when there are
           too many mails in the mailbox.  By default, the limit is 100.  If
           set to 0, sizes of all messages are downloaded at the start.
           This option does not work with ETRN or ODMR.  For POP3, the only
           valid non-zero value is 1.

      --fastuidl <number>
           (Keyword: fastuidl)
           Do a binary instead of linear search for the first unseen UID.
           Binary search avoids downloading the UIDs of all mails. This
           saves time (especially in daemon mode) where downloading the same
           set of UIDs in each poll is a waste of bandwidth. The number 'n'



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           indicates how rarely a linear search should be done. In daemon
           mode, linear search is used once followed by binary searches in
           'n-1' polls if 'n' is greater than 1; binary search is always
           used if 'n' is 1; linear search is always used if 'n' is 0. In
           non-daemon mode, binary search is used if 'n' is 1; otherwise
           linear search is used. The default value of 'n' is 4.  This
           option works with POP3 only.

      -e <count> | --expunge <count>
           (Keyword: expunge)
           Arrange for deletions to be made final after a given number of
           messages.  Under POP2 or POP3, fetchmail cannot make deletions
           final without sending QUIT and ending the session -- with this
           option on, fetchmail will break a long mail retrieval session
           into multiple sub-sessions, sending QUIT after each sub-session.
           This is a good defense against line drops on POP3 servers.  Under
           IMAP, fetchmail normally issues an EXPUNGE command after each
           deletion in order to force the deletion to be done immediately.
           This is safest when your connection to the server is flaky and
           expensive, as it avoids resending duplicate mail after a line
           hit.  However, on large mailboxes the overhead of re-indexing
           after every message can slam the server pretty hard, so if your
           connection is reliable it is good to do expunges less frequently.
           Also note that some servers enforce a delay of a few seconds
           after each quit, so fetchmail may not be able to get back in
           immediately after an expunge -- you may see "lock busy" errors if
           this happens. If you specify this option to an integer N, it
           tells fetchmail to only issue expunges on every Nth delete.  An
           argument of zero suppresses expunges entirely (so no expunges at
           all will be done until the end of run).  This option does not
           work with ETRN or ODMR.


    Authentication Options
      -u <name> | --user <name> |
           (Keyword: user[name])
           Specifies the user identification to be used when logging in to
           the mailserver.  The appropriate user identification is both
           server and user-dependent.  The default is your login name on the
           client machine that is running fetchmail.  See USER
           AUTHENTICATION below for a complete description.

      -I <specification> | --interface <specification>
           (Keyword: interface)
           Require that a specific interface device be up and have a
           specific local or remote IPv4 (IPv6 is not supported by this
           option yet) address (or range) before polling.  Frequently
           fetchmail is used over a transient point-to-point TCP/IP link
           established directly to a mailserver via SLIP or PPP.  That is a



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           relatively secure channel.  But when other TCP/IP routes to the
           mailserver exist (e.g. when the link is connected to an alternate
           ISP), your username and password may be vulnerable to snooping
           (especially when daemon mode automatically polls for mail,
           shipping a clear password over the net at predictable intervals).
           The --interface option may be used to prevent this.  When the
           specified link is not up or is not connected to a matching IP
           address, polling will be skipped.  The format is:

                interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]

           The field before the first slash is the interface name (i.e. sl0,
           ppp0 etc.).  The field before the second slash is the acceptable
           IP address.  The field after the second slash is a mask which
           specifies a range of IP addresses to accept.  If no mask is
           present 255.255.255.255 is assumed (i.e. an exact match).  This
           option is currently only supported under Linux and FreeBSD.
           Please see the monitor section for below for FreeBSD specific
           information.

           Note that this option may be removed from a future fetchmail
           version.

      -M <interface> | --monitor <interface>
           (Keyword: monitor)
           Daemon mode can cause transient links which are automatically
           taken down after a period of inactivity (e.g. PPP links) to
           remain up indefinitely.  This option identifies a system TCP/IP
           interface to be monitored for activity.  After each poll
           interval, if the link is up but no other activity has occurred on
           the link, then the poll will be skipped.  However, when fetchmail
           is woken up by a signal, the monitor check is skipped and the
           poll goes through unconditionally.  This option is currently only
           supported under Linux and FreeBSD.  For the monitor and interface
           options to work for non root users under FreeBSD, the fetchmail
           binary must be installed SGID kmem.  This would be a security
           hole, but fetchmail runs with the effective GID set to that of
           the kmem group only when interface data is being collected.

           Note that this option may be removed from a future fetchmail
           version.

      --auth <type>
           (Keyword: auth[enticate])
           This option permits you to specify an authentication type (see
           USER AUTHENTICATION below for details).  The possible values are
           any, password, kerberos_v5, kerberos (or, for excruciating
           exactness, kerberos_v4), gssapi, cram-md5, otp, ntlm, msn (only
           for POP3), external (only IMAP) and ssh.  When any (the default)



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           is specified, fetchmail tries first methods that don't require a
           password (EXTERNAL, GSSAPI, KERBEROS IV, KERBEROS 5); then it
           looks for methods that mask your password (CRAM-MD5, NTLM, X-OTP
           - note that MSN is only supported for POP3, but not autoprobed);
           and only if the server doesn't support any of those will it ship
           your password en clair.  Other values may be used to force
           various authentication methods (ssh suppresses authentication and
           is thus useful for IMAP PREAUTH).  (external suppresses
           authentication and is thus useful for IMAP EXTERNAL).  Any value
           other than password, cram-md5, ntlm, msn or otp suppresses
           fetchmail's normal inquiry for a password.  Specify ssh when you
           are using an end-to-end secure connection such as an ssh tunnel;
           specify external when you use TLS with client authentication and
           specify gssapi or kerberos_v4 if you are using a protocol variant
           that employs GSSAPI or K4.  Choosing KPOP protocol automatically
           selects Kerberos authentication.  This option does not work with
           ETRN.  GSSAPI service names are in line with RFC-2743 and IANA
           registrations, see

    Miscellaneous Options
      -f <pathname> | --fetchmailrc <pathname>
           Specify a non-default name for the ~/.fetchmailrc run control
           file.  The pathname argument must be either "-" (a single dash,
           meaning to read the configuration from standard input) or a
           filename.  Unless the --version option is also on, a named file
           argument must have permissions no more open than 0700
           (u=rwx,g=,o=) or else be /dev/null.

      -i <pathname> | --idfile <pathname>
           (Keyword: idfile)
           Specify an alternate name for the .fetchids file used to save
           message UIDs. NOTE: since fetchmail 6.3.0, write access to the
           directory containing the idfile is required, as fetchmail writes
           a temporary file and renames it into the place of the real idfile
           only if the temporary file has been written successfully. This
           avoids the truncation of idfiles when running out of disk space.

      --pidfile <pathname>
           (Keyword: pidfile; since fetchmail v6.3.4)
           Override the default location of the PID file. Default: see
           "ENVIRONMENT" below.

      -n | --norewrite
           (Keyword: no rewrite)
           Normally, fetchmail edits RFC-822 address headers (To, From, Cc,
           Bcc, and Reply-To) in fetched mail so that any mail IDs local to
           the server are expanded to full addresses (@ and the mailserver
           hostname are appended).  This enables replies on the client to
           get addressed correctly (otherwise your mailer might think they



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           should be addressed to local users on the client machine!).  This
           option disables the rewrite.  (This option is provided to pacify
           people who are paranoid about having an MTA edit mail headers and
           want to know they can prevent it, but it is generally not a good
           idea to actually turn off rewrite.) When using ETRN or ODMR, the
           rewrite option is ineffective.

      -E <line> | --envelope <line>
           (Keyword: envelope; Multidrop only)
           In the configuration file, an enhanced syntax is used:
           envelope [<count>] <line>

           This option changes the header fetchmail assumes will carry a
           copy of the mail's envelope address.  Normally this is
           'X-Envelope-To'.  Other typically found headers to carry envelope
           information are 'X-Original-To' and 'Delivered-To'.  Now, since
           these headers are not standardized, practice varies. See the
           discussion of multidrop address handling below.  As a special
           case, 'envelope "Received"' enables parsing of sendmail-style
           Received lines.  This is the default, but discouraged because it
           is not fully reliable.

           Note that fetchmail expects the Received-line to be in a specific
           format: It must contain "by host for address", where host must
           match one of the mailserver names that fetchmail recognizes for
           the account in question.

           The optional count argument (only available in the configuration
           file) determines how many header lines of this kind are skipped.
           A count of 1 means: skip the first, take the second. A count of 2
           means: skip the first and second, take the third, and so on.

      -Q <prefix> | --qvirtual <prefix>
           (Keyword: qvirtual; Multidrop only)
           The string prefix assigned to this option will be removed from
           the user name found in the header specified with the envelope
           option (before doing multidrop name mapping or localdomain
           checking, if either is applicable). This option is useful if you
           are using fetchmail to collect the mail for an entire domain and
           your ISP (or your mail redirection provider) is using qmail.  One
           of the basic features of qmail is the Delivered-To: message
           header.  Whenever qmail delivers a message to a local mailbox it
           puts the username and hostname of the envelope recipient on this
           line.  The major reason for this is to prevent mail loops.  To
           set up qmail to batch mail for a disconnected site the ISP-
           mailhost will have normally put that site in its 'Virtualhosts'
           control file so it will add a prefix to all mail addresses for
           this site. This results in mail sent to
           'username@userhost.userdom.dom.com' having a Delivered-To: line



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           of the form:

           Delivered-To: mbox-userstr-username@userhost.example.com

      The ISP can make the 'mbox-userstr-' prefix anything they choose but a
      string matching the user host name is likely.  By using the option
      'envelope Delivered-To:' you can make fetchmail reliably identify the
      original envelope recipient, but you have to strip the 'mbox-userstr-'
      prefix to deliver to the correct user.  This is what this option is
      for.

      --configdump
           Parse the ~/.fetchmailrc file, interpret any command-line options
           specified, and dump a configuration report to standard output.
           The configuration report is a data structure assignment in the
           language Python.  This option is meant to be used with an
           interactive ~/.fetchmailrc editor like fetchmailconf, written in
           Python.


    Removed Options
      -T | --netsec
           Removed before version 6.3.0, the required underlying inet6_apps
           library had been discontinued and is no longer available.


 USER AUTHENTICATION AND ENCRYPTION
      All modes except ETRN require authentication of the client to the
      server.  Normal user authentication in fetchmail is very much like the
      authentication mechanism of ftp(1).  The correct user-id and password
      depend upon the underlying security system at the mailserver.

      If the mailserver is a Unix machine on which you have an ordinary user
      account, your regular login name and password are used with fetchmail.
      If you use the same login name on both the server and the client
      machines, you needn't worry about specifying a user-id with the -u
      option -- the default behavior is to use your login name on the client
      machine as the user-id on the server machine.  If you use a different
      login name on the server machine, specify that login name with the -u
      option.  e.g. if your login name is 'jsmith' on a machine named
      'mailgrunt', you would start fetchmail as follows:

           fetchmail -u jsmith mailgrunt

      The default behavior of fetchmail is to prompt you for your mailserver
      password before the connection is established.  This is the safest way
      to use fetchmail and ensures that your password will not be
      compromised.  You may also specify your password in your
      ~/.fetchmailrc file.  This is convenient when using fetchmail in



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      daemon mode or with scripts.


    Using netrc files
      If you do not specify a password, and fetchmail cannot extract one
      from your ~/.fetchmailrc file, it will look for a ~/.netrc file in
      your home directory before requesting one interactively; if an entry
      matching the mailserver is found in that file, the password will be
      used.  Fetchmail first looks for a match on poll name; if it finds
      none, it checks for a match on via name.  See the ftp(1) man page for
      details of the syntax of the ~/.netrc file.  To show a practical
      example, a .netrc might look like this:


           machine hermes.example.org
           login joe
           password topsecret

      You can repeat this block with different user information if you need
      to provide more than one password.

      This feature may allow you to avoid duplicating password information
      in more than one file.

      On mailservers that do not provide ordinary user accounts, your user-
      id and password are usually assigned by the server administrator when
      you apply for a mailbox on the server.  Contact your server
      administrator if you don't know the correct user-id and password for
      your mailbox account.

 POP3 VARIANTS
      Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
      independent authentication using the .rhosts file on the mailserver
      side.  Under this RPOP variant, a fixed per-user ID equivalent to a
      password was sent in clear over a link to a reserved port, with the
      command RPOP rather than PASS to alert the server that it should do
      special checking.  RPOP is supported by fetchmail (you can specify
      'protocol RPOP' to have the program send 'RPOP' rather than 'PASS')
      but its use is strongly discouraged, and support will be removed from
      a future fetchmail version.  This facility was vulnerable to spoofing
      and was withdrawn in RFC1460.

      RFC1460 introduced APOP authentication.  In this variant of POP3, you
      register an APOP password on your server host (on some servers, the
      program to do this is called popauth(8)).  You put the same password
      in your ~/.fetchmailrc file.  Each time fetchmail logs in, it sends an
      MD5 hash of your password and the server greeting time to the server,
      which can verify it by checking its authorization database.




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      Note that APOP is no longer considered resistant against man-in-the-
      middle attacks.

    RETR or TOP
      fetchmail makes some efforts to make the server believe messages had
      not been retrieved, by using the TOP command with a large number of
      lines when possible.  TOP is a command that retrieves the full header
      and a fetchmail-specified amount of body lines. It is optional and
      therefore not implemented by all servers, and some are known to
      implement it improperly. On many servers however, the RETR command
      which retrieves the full message with header and body, sets the "seen"
      flag (for instance, in a web interface), whereas the TOP command does
      not do that.

      fetchmail will always use the RETR command if "fetchall" is set.
      fetchmail will also use the RETR command if "keep" is set and "uidl"
      is unset.  Finally, fetchmail will use the RETR command on Maillennium
      POP3/PROXY servers (used by Comcast) to avoid a deliberate TOP
      misinterpretation in this server that causes message corruption.

      In all other cases, fetchmail will use the TOP command. This implies
      that in "keep" setups, "uidl" must be set if "TOP" is desired.

      Note that this description is true for the current version of
      fetchmail, but the behavior may change in future versions. In
      particular, fetchmail may prefer the RETR command because the TOP
      command causes much grief on some servers and is only optional.

 ALTERNATE AUTHENTICATION FORMS
      If your fetchmail was built with Kerberos support and you specify
      Kerberos authentication (either with --auth or the .fetchmailrc option
      authenticate kerberos_v4) it will try to get a Kerberos ticket from
      the mailserver at the start of each query.  Note: if either the
      pollname or via name is 'hesiod', fetchmail will try to use Hesiod to
      look up the mailserver.

      If you use POP3 or IMAP with GSSAPI authentication, fetchmail will
      expect the server to have RFC1731- or RFC1734-conforming GSSAPI
      capability, and will use it.  Currently this has only been tested over
      Kerberos V, so you're expected to already have a ticket-granting
      ticket. You may pass a username different from your principal name
      using the standard --user command or by the .fetchmailrc option user.

      If your IMAP daemon returns the PREAUTH response in its greeting line,
      fetchmail will notice this and skip the normal authentication step.
      This can be useful, e.g. if you start imapd explicitly using ssh.  In
      this case you can declare the authentication value 'ssh' on that site
      entry to stop .fetchmail from asking you for a password when it starts
      up.



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      If you use client authentication with TLS1 and your IMAP daemon
      returns the AUTH=EXTERNAL response, fetchmail will notice this and
      will use the authentication shortcut and will not send the passphrase.
      In this case you can declare the authentication value 'external'
       on that site to stop fetchmail from asking you for a password when it
      starts up.

      If you are using POP3, and the server issues a one-time-password
      challenge conforming to RFC1938, fetchmail will use your password as a
      pass phrase to generate the required response. This avoids sending
      secrets over the net unencrypted.

      Compuserve's RPA authentication is supported. If you compile in the
      support, fetchmail will try to perform an RPA pass-phrase
      authentication instead of sending over the password en clair if it
      detects "@compuserve.com" in the hostname.

      If you are using IMAP, Microsoft's NTLM authentication (used by
      Microsoft Exchange) is supported. If you compile in the support,
      fetchmail will try to perform an NTLM authentication (instead of
      sending over the password en clair) whenever the server returns
      AUTH=NTLM in its capability response. Specify a user option value that
      looks like 'user@domain': the part to the left of the @ will be passed
      as the username and the part to the right as the NTLM domain.


    Secure Socket Layers (SSL) and Transport
      Note that fetchmail currently uses the OpenSSL library, which is
      severely underdocumented, so failures may occur just because the
      programmers are not aware of OpenSSL's requirement of the day.  For
      instance, since v6.3.16, fetchmail calls OpenSSL_add_all_algorithms(),
      which is necessary to support certificates using SHA256 on OpenSSL
      0.9.8 -- this information is deeply hidden in the documentation and
      not at all obvious.  Please do not hesitate to report subtle SSL
      failures.

      You can access SSL encrypted services by specifying the --ssl option.
      You can also do this using the "ssl" user option in the .fetchmailrc
      file. With SSL encryption enabled, queries are initiated over a
      connection after negotiating an SSL session, and the connection fails
      if SSL cannot be negotiated.  Some services, such as POP3 and IMAP,
      have different well known ports defined for the SSL encrypted
      services.  The encrypted ports will be selected automatically when SSL
      is enabled and no explicit port is specified. The --sslproto 'SSL3'
      option should be used to select the SSLv3 protocol (default if unset:
      v2 or v3).  Also, the --sslcertck command line or sslcertck run
      control file option should be used to force strict certificate
      checking - see below.




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      If SSL is not configured, fetchmail will usually opportunistically try
      to use STARTTLS. STARTTLS can be enforced by using --sslproto "TLS1".
      TLS connections use the same port as the unencrypted version of the
      protocol and negotiate TLS via special command. The --sslcertck
      command line or sslcertck run control file option should be used to
      force strict certificate checking - see below.

      --sslcertck is recommended: When connecting to an SSL or TLS encrypted
      server, the server presents a certificate to the client for
      validation.  The certificate is checked to verify that the common name
      in the certificate matches the name of the server being contacted and
      that the effective and expiration dates in the certificate indicate
      that it is currently valid.  If any of these checks fail, a warning
      message is printed, but the connection continues.  The server
      certificate does not need to be signed by any specific Certifying
      Authority and may be a "self-signed" certificate. If the --sslcertck
      command line option or sslcertck run control file option is used,
      fetchmail will instead abort if any of these checks fail, because it
      must assume that there is a man-in-the-middle attack in this scenario,
      hence fetchmail must not expose cleartext passwords. Use of the
      sslcertck or --sslcertck option is therefore advised.

      Some SSL encrypted servers may request a client side certificate.  A
      client side public SSL certificate and private SSL key may be
      specified.  If requested by the server, the client certificate is sent
      to the server for validation.  Some servers may require a valid client
      certificate and may refuse connections if a certificate is not
      provided or if the certificate is not valid.  Some servers may require
      client side certificates be signed by a recognized Certifying
      Authority.  The format for the key files and the certificate files is
      that required by the underlying SSL libraries (OpenSSL in the general
      case).

      A word of care about the use of SSL: While above mentioned setup with
      self-signed server certificates retrieved over the wires can protect
      you from a passive eavesdropper, it doesn't help against an active
      attacker. It's clearly an improvement over sending the passwords in
      clear, but you should be aware that a man-in-the-middle attack is
      trivially possible (in particular with tools such as ).  Use of strict
      certificate checking with a certification authority recognized by
      server and client, or perhaps of an SSH tunnel (see below for some
      examples) is preferable if you care seriously about the security of
      your mailbox and passwords.


    ESMTP AUTH
      fetchmail also supports authentication to the ESMTP server on the
      client side according to RFC 2554.  You can specify a name/password
      pair to be used with the keywords 'esmtpname' and 'esmtppassword'; the



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      former defaults to the username of the calling user.


 DAEMON MODE
    Introducing the daemon mode
      In daemon mode, fetchmail puts itself into the background and runs
      forever, querying each specified host and then sleeping for a given
      polling interval.

    Starting the daemon mode
      There are several ways to make fetchmail work in daemon mode. On the
      command line, --daemon <interval> or -d <interval> option runs
      fetchmail in daemon mode.  You must specify a numeric argument which
      is a polling interval (time to wait after completing a whole poll
      cycle with the last server and before starting the next poll cycle
      with the first server) in seconds.

      Example: simply invoking

           fetchmail -d 900

      will, therefore, poll all the hosts described in your ~/.fetchmailrc
      file (except those explicitly excluded with the 'skip' verb) a bit
      less often than once every 15 minutes (exactly: 15 minutes + time that
      the poll takes).

      It is also possible to set a polling interval in your ~/.fetchmailrc
      file by saying 'set daemon <interval>', where <interval> is an integer
      number of seconds.  If you do this, fetchmail will always start in
      daemon mode unless you override it with the command-line option
      --daemon 0 or -d0.

      Only one daemon process is permitted per user; in daemon mode,
      fetchmail sets up a per-user lockfile to guarantee this.  (You can
      however cheat and set the FETCHMAILHOME environment variable to
      overcome this setting, but in that case, it is your responsibility to
      make sure you aren't polling the same server with two processes at the
      same time.)

    Awakening the background daemon
      Normally, calling fetchmail with a daemon in the background sends a
      wake-up signal to the daemon and quits without output. The background
      daemon then starts its next poll cycle immediately.  The wake-up
      signal, SIGUSR1, can also be sent manually. The wake-up action also
      clears any 'wedged' flags indicating that connections have wedged due
      to failed authentication or multiple timeouts.

    Terminating the background daemon
      The option --quit will kill a running daemon process instead of waking



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      it up (if there is no such process, fetchmail will notify you).  If
      the --quit option appears last on the command line, fetchmail will
      kill the running daemon process and then quit. Otherwise, fetchmail
      will first kill a running daemon process and then continue running
      with the other options.

    Useful options for daemon mode
      The -L <filename> or --logfile <filename> option (keyword: set
      logfile) is only effective when fetchmail is detached and in daemon
      mode. Note that the logfile must exist before fetchmail is run, you
      can use the touch(1) command with the filename as its sole argument to
      create it.
      This option allows you to redirect status messages into a specified
      logfile (follow the option with the logfile name).  The logfile is
      opened for append, so previous messages aren't deleted.  This is
      primarily useful for debugging configurations. Note that fetchmail
      does not detect if the logfile is rotated, the logfile is only opened
      once when fetchmail starts. You need to restart fetchmail after
      rotating the logfile and before compressing it (if applicable).

      The --syslog option (keyword: set syslog) allows you to redirect
      status and error messages emitted to the syslog(3) system daemon if
      available.  Messages are logged with an id of fetchmail, the facility
      LOG_MAIL, and priorities LOG_ERR, LOG_ALERT or LOG_INFO.  This option
      is intended for logging status and error messages which indicate the
      status of the daemon and the results while fetching mail from the
      server(s).  Error messages for command line options and parsing the
      .fetchmailrc file are still written to stderr, or to the specified log
      file.  The --nosyslog option turns off use of syslog(3), assuming it's
      turned on in the ~/.fetchmailrc file.  This option is overridden, in
      certain situations, by --logfile (which see).

      The -N or --nodetach option suppresses backgrounding and detachment of
      the daemon process from its control terminal.  This is useful for
      debugging or when fetchmail runs as the child of a supervisor process
      such as init(8) or Gerrit Pape's runit(8).  Note that this also causes
      the logfile option to be ignored.

      Note that while running in daemon mode polling a POP2 or IMAP2bis
      server, transient errors (such as DNS failures or sendmail delivery
      refusals) may force the fetchall option on for the duration of the
      next polling cycle.  This is a robustness feature.  It means that if a
      message is fetched (and thus marked seen by the mailserver) but not
      delivered locally due to some transient error, it will be re-fetched
      during the next poll cycle.  (The IMAP logic doesn't delete messages
      until they're delivered, so this problem does not arise.)

      If you touch or change the ~/.fetchmailrc file while fetchmail is
      running in daemon mode, this will be detected at the beginning of the



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      next poll cycle.  When a changed ~/.fetchmailrc is detected, fetchmail
      rereads it and restarts from scratch (using exec(2); no state
      information is retained in the new instance).  Note that if fetchmail
      needs to query for passwords, of that if you break the ~/.fetchmailrc
      file's syntax, the new instance will softly and silently vanish away
      on startup.


 ADMINISTRATIVE OPTIONS
      The --postmaster <name> option (keyword: set postmaster) specifies the
      last-resort username to which multidrop mail is to be forwarded if no
      matching local recipient can be found. It is also used as destination
      of undeliverable mail if the 'bouncemail' global option is off and
      additionally for spam-blocked mail if the 'bouncemail' global option
      is off and the 'spambounce' global option is on. This option defaults
      to the user who invoked fetchmail.  If the invoking user is root, then
      the default of this option is the user 'postmaster'.  Setting
      postmaster to the empty string causes such mail as described above to
      be discarded - this however is usually a bad idea.  See also the
      description of the 'FETCHMAILUSER' environment variable in the
      ENVIRONMENT section below.

      The --nobounce behaves like the "set no bouncemail" global option,
      which see.

      The --invisible option (keyword: set invisible) tries to make
      fetchmail invisible.  Normally, fetchmail behaves like any other MTA
      would -- it generates a Received header into each message describing
      its place in the chain of transmission, and tells the MTA it forwards
      to that the mail came from the machine fetchmail itself is running on.
      If the invisible option is on, the Received header is suppressed and
      fetchmail tries to spoof the MTA it forwards to into thinking it came
      directly from the mailserver host.

      The --showdots option (keyword: set showdots) forces fetchmail to show
      progress dots even if the output goes to a file or fetchmail is not in
      verbose mode.  Fetchmail shows the dots by default when run in
      --verbose mode and output goes to console. This option is ignored in
      --silent mode.

      By specifying the --tracepolls option, you can ask fetchmail to add
      information to the Received header on the form "polling {label}
      account {user}", where {label} is the account label (from the
      specified rcfile, normally ~/.fetchmailrc) and {user} is the username
      which is used to log on to the mail server. This header can be used to
      make filtering email where no useful header information is available
      and you want mail from different accounts sorted into different
      mailboxes (this could, for example, occur if you have an account on
      the same server running a mailing list, and are subscribed to the list



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      using that account). The default is not adding any such header.  In
      .fetchmailrc, this is called 'tracepolls'.


 RETRIEVAL FAILURE MODES
      The protocols fetchmail uses to talk to mailservers are next to
      bulletproof.  In normal operation forwarding to port 25, no message is
      ever deleted (or even marked for deletion) on the host until the SMTP
      listener on the client side has acknowledged to fetchmail that the
      message has been either accepted for delivery or rejected due to a
      spam block.

      When forwarding to an MDA, however, there is more possibility of
      error.  Some MDAs are 'safe' and reliably return a nonzero status on
      any delivery error, even one due to temporary resource limits.  The
      maildrop(1) program is like this; so are most programs designed as
      mail transport agents, such as sendmail(1), including the sendmail
      wrapper of Postfix and exim(1).  These programs give back a reliable
      positive acknowledgement and can be used with the mda option with no
      risk of mail loss.  Unsafe MDAs, though, may return 0 even on delivery
      failure.  If this happens, you will lose mail.

      The normal mode of fetchmail is to try to download only 'new'
      messages, leaving untouched (and undeleted) messages you have already
      read directly on the server (or fetched with a previous fetchmail
      --keep).  But you may find that messages you've already read on the
      server are being fetched (and deleted) even when you don't specify
      --all.  There are several reasons this can happen.

      One could be that you're using POP2.  The POP2 protocol includes no
      representation of 'new' or 'old' state in messages, so fetchmail must
      treat all messages as new all the time.  But POP2 is obsolete, so this
      is unlikely.

      A potential POP3 problem might be servers that insert messages in the
      middle of mailboxes (some VMS implementations of mail are rumored to
      do this).  The fetchmail code assumes that new messages are appended
      to the end of the mailbox; when this is not true it may treat some old
      messages as new and vice versa.  Using UIDL whilst setting fastuidl 0
      might fix this, otherwise, consider switching to IMAP.

      Yet another POP3 problem is that if they can't make tempfiles in the
      user's home directory, some POP3 servers will hand back an
      undocumented response that causes fetchmail to spuriously report "No
      mail".

      The IMAP code uses the presence or absence of the server flag \Seen to
      decide whether or not a message is new.  This isn't the right thing to
      do, fetchmail should check the UIDVALIDITY and use UID, but it doesn't



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      do that yet. Under Unix, it counts on your IMAP server to notice the
      BSD-style Status flags set by mail user agents and set the \Seen flag
      from them when appropriate.  All Unix IMAP servers we know of do this,
      though it's not specified by the IMAP RFCs.  If you ever trip over a
      server that doesn't, the symptom will be that messages you have
      already read on your host will look new to the server.  In this
      (unlikely) case, only messages you fetched with fetchmail --keep will
      be both undeleted and marked old.

      In ETRN and ODMR modes, fetchmail does not actually retrieve messages;
      instead, it asks the server's SMTP listener to start a queue flush to
      the client via SMTP.  Therefore it sends only undelivered messages.


 SPAM FILTERING
      Many SMTP listeners allow administrators to set up 'spam filters' that
      block unsolicited email from specified domains.  A MAIL FROM or DATA
      line that triggers this feature will elicit an SMTP response which
      (unfortunately) varies according to the listener.

      Newer versions of sendmail return an error code of 571.

      According to RFC2821, the correct thing to return in this situation is
      550 "Requested action not taken: mailbox unavailable" (the draft adds
      "[E.g., mailbox not found, no access, or command rejected for policy
      reasons].").

      Older versions of the exim MTA return 501 "Syntax error in parameters
      or arguments".

      The postfix MTA runs 554 as an antispam response.

      Zmailer may reject code with a 500 response (followed by an enhanced
      status code that contains more information).

      Return codes which fetchmail treats as antispam responses and discards
      the message can be set with the 'antispam' option.  This is one of the
      only three circumstance under which fetchmail ever discards mail (the
      others are the 552 and 553 errors described below, and the suppression
      of multidropped messages with a message-ID already seen).

      If fetchmail is fetching from an IMAP server, the antispam response
      will be detected and the message rejected immediately after the
      headers have been fetched, without reading the message body.  Thus,
      you won't pay for downloading spam message bodies.

      By default, the list of antispam responses is empty.

      If the spambounce global option is on, mail that is spam-blocked



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      triggers an RFC1892/RFC1894 bounce message informing the originator
      that we do not accept mail from it. See also BUGS.


 SMTP/ESMTP ERROR HANDLING
      Besides the spam-blocking described above, fetchmail takes special
      actions - that may be modified by the --softbounce option - on the
      following SMTP/ESMTP error response codes

      452 (insufficient system storage)
           Leave the message in the server mailbox for later retrieval.

      552 (message exceeds fixed maximum message size)
           Delete the message from the server.  Send bounce-mail to the
           originator.

      553 (invalid sending domain)
           Delete the message from the server.  Don't even try to send
           bounce-mail to the originator.

      Other errors greater or equal to 500 trigger bounce mail back to the
      originator, unless suppressed by --softbounce. See also BUGS.


 THE RUN CONTROL FILE
      The preferred way to set up fetchmail is to write a .fetchmailrc file
      in your home directory (you may do this directly, with a text editor,
      or indirectly via fetchmailconf).  When there is a conflict between
      the command-line arguments and the arguments in this file, the
      command-line arguments take precedence.

      To protect the security of your passwords, your ~/.fetchmailrc may not
      normally have more than 0700 (u=rwx,g=,o=) permissions; fetchmail will
      complain and exit otherwise (this check is suppressed when --version
      is on).

      You may read the .fetchmailrc file as a list of commands to be
      executed when fetchmail is called with no arguments.

    Run Control Syntax
      Comments begin with a '#' and extend through the end of the line.
      Otherwise the file consists of a series of server entries or global
      option statements in a free-format, token-oriented syntax.

      There are four kinds of tokens: grammar keywords, numbers (i.e.
      decimal digit sequences), unquoted strings, and quoted strings.  A
      quoted string is bounded by double quotes and may contain whitespace
      (and quoted digits are treated as a string).  Note that quoted strings
      will also contain line feed characters if they run across two or more



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      lines, unless you use a backslash to join lines (see below).  An
      unquoted string is any whitespace-delimited token that is neither
      numeric, string quoted nor contains the special characters ',', ';',
      ':', or '='.

      Any amount of whitespace separates tokens in server entries, but is
      otherwise ignored. You may use backslash escape sequences (\n for LF,
      \t for HT, \b for BS, \r for CR, \nnn for decimal (where nnn cannot
      start with a 0), \0ooo for octal, and \xhh for hex) to embed non-
      printable characters or string delimiters in strings.  In quoted
      strings, a backslash at the very end of a line will cause the
      backslash itself and the line feed (LF or NL, new line) character to
      be ignored, so that you can wrap long strings. Without the backslash
      at the line end, the line feed character would become part of the
      string.

      Warning: while these resemble C-style escape sequences, they are not
      the same.  fetchmail only supports these eight styles. C supports more
      escape sequences that consist of backslash (\) and a single character,
      but does not support decimal codes and does not require the leading 0
      in octal notation.  Example: fetchmail interprets \233 the same as
      \xE9 (Latin small letter e with acute), where C would interpret \233
      as octal 0233 = \x9B (CSI, control sequence introducer).

      Each server entry consists of one of the keywords 'poll' or 'skip',
      followed by a server name, followed by server options, followed by any
      number of user (or username) descriptions, followed by user options.
      Note: the most common cause of syntax errors is mixing up user and
      server options or putting user options before the user descriptions.

      For backward compatibility, the word 'server' is a synonym for 'poll'.

      You can use the noise keywords 'and', 'with', 'has', 'wants', and
      'options' anywhere in an entry to make it resemble English.  They're
      ignored, but but can make entries much easier to read at a glance.
      The punctuation characters ':', ';' and ',' are also ignored.

    Poll vs. Skip
      The 'poll' verb tells fetchmail to query this host when it is run with
      no arguments.  The 'skip' verb tells fetchmail not to poll this host
      unless it is explicitly named on the command line.  (The 'skip' verb
      allows you to experiment with test entries safely, or easily disable
      entries for hosts that are temporarily down.)

    Keyword/Option Summary
      Here are the legal options.  Keyword suffixes enclosed in square
      brackets are optional.  Those corresponding to short command-line
      options are followed by '-' and the appropriate option letter.  If
      option is only relevant to a single mode of operation, it is noted as



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      's' or 'm' for singledrop- or multidrop-mode, respectively.

      Here are the legal global options:

      l l l lw34.  Keyword   Opt  Mode Function _ set daemon
         -d        T{ Set a background poll interval in seconds.  T} set
      postmaster                T{ Give the name of the last-resort mail
      recipient (default: user running fetchmail, "postmaster" if run by the
      root user) T} set    bouncemail             T{ Direct error mail to
      the sender (default) T} set no bouncemail             T{ Direct error
      mail to the local postmaster (as per the 'postmaster' global option
      above).  T} set no spambounce             T{ Do not bounce spam-
      blocked mail (default).  T} set    spambounce             T{ Bounce
      blocked spam-blocked mail (as per the 'antispam' user option) back to
      the destination as indicated by the 'bouncemail' global option.
      Warning: Do not use this to bounce spam back to the sender - most spam
      is sent with false sender address and thus this option hurts innocent
      bystanders.  T} set no softbounce             T{ Delete permanently
      undeliverable mail. It is recommended to use this option if the
      configuration has been thoroughly tested.  T} set
      softbounce             T{ Keep permanently undeliverable mail as
      though a temporary error had occurred (default).  T} set logfile
        -L        T{ Name of a file to append error and status messages to.
      Only effective in daemon mode and if fetchmail detaches.  If
      effective, overrides set syslog.  T} set idfile     -i        T{ Name
      of the file to store UID lists in.  T} set    syslog            T{ Do
      error logging through syslog(3). May be overriden by set logfile.  T}
      set no syslog                 T{ Turn off error logging through
      syslog(3). (default) T} set properties                T{ String value
      that is ignored by fetchmail (may be used by extension scripts).  T}

      Here are the legal server options:

      l l l lw34.  Keyword   Opt  Mode Function _ via                 T{
      Specify DNS name of mailserver, overriding poll name T}
      proto[col]     -p        T{ Specify protocol (case insensitive): POP2,
      POP3, IMAP, APOP, KPOP T} local[domains]      m    T{ Specify
      domain(s) to be regarded as local T} port                T{ Specify
      TCP/IP service port (obsolete, use 'service' instead).  T} service
        -P        T{ Specify service name (a numeric value is also allowed
      and considered a TCP/IP port number).  T} auth[enticate]           T{
      Set authentication type (default 'any') T} timeout   -t        T{
      Server inactivity timeout in seconds (default 300) T}
      envelope  -E   m    T{ Specify envelope-address header name T} no
      envelope         m    T{ Disable looking for envelope address T}
      qvirtual  -Q   m    T{ Qmail virtual domain prefix to remove from user
      name T} aka            m    T{ Specify alternate DNS names of
      mailserver T} interface -I        T{ specify IP interface(s) that must
      be up for server poll to take place T} monitor        -M        T{



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      Specify IP address to monitor for activity T} plugin              T{
      Specify command through which to make server connections.  T} plugout
                     T{ Specify command through which to make listener
      connections.  T} dns            m    T{ Enable DNS lookup for
      multidrop (default) T} no dns         m    T{ Disable DNS lookup for
      multidrop T} checkalias          m    T{ Do comparison by IP address
      for multidrop T} no checkalias       m    T{ Do comparison by name for
      multidrop (default) T} uidl      -U        T{ Force POP3 to use
      client-side UIDLs (recommended) T} no uidl                  T{ Turn
      off POP3 use of client-side UIDLs (default) T} interval
                    T{ Only check this site every N poll cycles; N is a
      numeric argument.  T} tracepolls               T{ Add poll tracing
      information to the Received header T} principal                T{ Set
      Kerberos principal (only useful with IMAP and kerberos) T} esmtpname
                   T{ Set name for RFC2554 authentication to the ESMTP
      server.  T} esmtppassword            T{ Set password for RFC2554
      authentication to the ESMTP server.  T} bad-header               T{
      How to treat messages with a bad header. Can be reject (default) or
      accept.  T}

      Here are the legal user descriptions and options:

      l l l lw34.  Keyword   Opt  Mode Function _
      user[name]     -u        T{ This is the user description and must come
      first after server description and after possible server options, and
      before user options.
      It sets the remote user name if by itself or followed by 'there', or
      the local user name if followed by 'here'.  T} is                  T{
      Connect local and remote user names T} to                  T{ Connect
      local and remote user names T} pass[word]               T{ Specify
      remote account password T} ssl                 T{ Connect to server
      over the specified base protocol using SSL encryption T} sslcert
                  T{ Specify file for client side public SSL certificate T}
      sslcertfile              T{ Specify file with trusted CA certificates
      T} sslcertpath              T{ Specify c_rehash-ed directory with
      trusted CA certificates.  T} sslkey              T{ Specify file for
      client side private SSL key T} sslproto            T{ Force ssl
      protocol for connection T} folder    -r        T{ Specify remote
      folder to query T} smtphost  -S        T{ Specify smtp host(s) to
      forward to T} fetchdomains        m    T{ Specify domains for which
      mail should be fetched T} smtpaddress    -D        T{ Specify the
      domain to be put in RCPT TO lines T} smtpname            T{ Specify
      the user and domain to be put in RCPT TO lines T}
      antispam  -Z        T{ Specify what SMTP returns are interpreted as
      spam-policy blocks T} mda       -m        T{ Specify MDA for local
      delivery T} bsmtp     -o        T{ Specify BSMTP batch file to append
      to T} preconnect               T{ Command to be executed before each
      connection T} postconnect              T{ Command to be executed after
      each connection T} keep      -k        T{ Don't delete seen messages



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      from server (for POP3, uidl is recommended) T} flush     -F        T{
      Flush all seen messages before querying (DANGEROUS) T} limitflush
                  T{ Flush all oversized messages before querying T}
      fetchall  -a        T{ Fetch all messages whether seen or not T}
      rewrite                  T{ Rewrite destination addresses for reply
      (default) T} stripcr             T{ Strip carriage returns from ends
      of lines T} forcecr             T{ Force carriage returns at ends of
      lines T} pass8bits           T{ Force BODY=8BITMIME to ESMTP listener
      T} dropstatus               T{ Strip Status and X-Mozilla-Status lines
      out of incoming mail T} dropdelivered            T{ Strip Delivered-To
      lines out of incoming mail T} mimedecode               T{ Convert
      quoted-printable to 8-bit in MIME messages T} idle                T{
      Idle waiting for new messages after each poll (IMAP only) T} no keep
       -K        T{ Delete seen messages from server (default) T} no
      flush            T{ Don't flush all seen messages before querying
      (default) T} no fetchall              T{ Retrieve only new messages
      (default) T} no rewrite               T{ Don't rewrite headers T} no
      stripcr               T{ Don't strip carriage returns (default) T} no
      forcecr               T{ Don't force carriage returns at EOL (default)
      T} no pass8bits             T{ Don't force BODY=8BITMIME to ESMTP
      listener (default) T} no dropstatus            T{ Don't drop Status
      headers (default) T} no dropdelivered              T{ Don't drop
      Delivered-To headers (default) T} no mimedecode            T{ Don't
      convert quoted-printable to 8-bit in MIME messages (default) T} no
      idle                  T{ Don't idle waiting for new messages after
      each poll (IMAP only) T} limit     -l        T{ Set message size limit
      T} warnings       -w        T{ Set message size warning interval T}
      batchlimit     -b        T{ Max # messages to forward in single
      connect T} fetchlimit     -B        T{ Max # messages to fetch in
      single connect T} fetchsizelimit           T{ Max # message sizes to
      fetch in single transaction T} fastuidl            T{ Use binary
      search for first unseen message (POP3 only) T} expunge   -e        T{
      Perform an expunge on every #th message (IMAP and POP3 only) T}
      properties               T{ String value is ignored by fetchmail (may
      be used by extension scripts) T}

      All user options must begin with a user description (user or username
      option) and follow all server descriptions and options.

      In the .fetchmailrc file, the 'envelope' string argument may be
      preceded by a whitespace-separated number.  This number, if specified,
      is the number of such headers to skip over (that is, an argument of 1
      selects the second header of the given type).  This is sometime useful
      for ignoring bogus envelope headers created by an ISP's local delivery
      agent or internal forwards (through mail inspection systems, for
      instance).

    Keywords Not Corresponding To Option Switches
      The 'folder' and 'smtphost' options (unlike their command-line



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      equivalents) can take a space- or comma-separated list of names
      following them.

      All options correspond to the obvious command-line arguments, except
      the following: 'via', 'interval', 'aka', 'is', 'to', 'dns'/'no dns',
      'checkalias'/'no checkalias', 'password', 'preconnect', 'postconnect',
      'localdomains', 'stripcr'/'no stripcr', 'forcecr'/'no forcecr',
      'pass8bits'/'no pass8bits' 'dropstatus/no dropstatus',
      'dropdelivered/no dropdelivered', 'mimedecode/no mimedecode', 'no
      idle', and 'no envelope'.

      The 'via' option is for if you want to have more than one
      configuration pointing at the same site.  If it is present, the string
      argument will be taken as the actual DNS name of the mailserver host
      to query.  This will override the argument of poll, which can then
      simply be a distinct label for the configuration (e.g. what you would
      give on the command line to explicitly query this host).

      The 'interval' option (which takes a numeric argument) allows you to
      poll a server less frequently than the basic poll interval.  If you
      say 'interval N' the server this option is attached to will only be
      queried every N poll intervals.

    Singledrop vs. Multidrop options
      Please ensure you read the section titled THE USE AND ABUSE OF
      MULTIDROP MAILBOXES if you intend to use multidrop mode.

      The 'is' or 'to' keywords associate the following local (client)
      name(s) (or server-name to client-name mappings separated by =) with
      the mailserver user name in the entry.  If an is/to list has '*' as
      its last name, unrecognized names are simply passed through. Note that
      until fetchmail version 6.3.4 inclusively, these lists could only
      contain local parts of user names (fetchmail would only look at the
      part before the @ sign). fetchmail versions 6.3.5 and newer support
      full addresses on the left hand side of these mappings, and they take
      precedence over any 'localdomains', 'aka', 'via' or similar mappings.

      A single local name can be used to support redirecting your mail when
      your username on the client machine is different from your name on the
      mailserver.  When there is only a single local name, mail is forwarded
      to that local username regardless of the message's Received, To, Cc,
      and Bcc headers.  In this case, fetchmail never does DNS lookups.

      When there is more than one local name (or name mapping), fetchmail
      looks at the envelope header, if configured, and otherwise at the
      Received, To, Cc, and Bcc headers of retrieved mail (this is
      'multidrop mode').  It looks for addresses with hostname parts that
      match your poll name or your 'via', 'aka' or 'localdomains' options,
      and usually also for hostname parts which DNS tells it are aliases of



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      the mailserver.  See the discussion of 'dns', 'checkalias',
      'localdomains', and 'aka' for details on how matching addresses are
      handled.

      If fetchmail cannot match any mailserver usernames or localdomain
      addresses, the mail will be bounced.  Normally it will be bounced to
      the sender, but if the 'bouncemail' global option is off, the mail
      will go to the local postmaster instead.  (see the 'postmaster' global
      option). See also BUGS.

      The 'dns' option (normally on) controls the way addresses from
      multidrop mailboxes are checked.  On, it enables logic to check each
      host address that does not match an 'aka' or 'localdomains'
      declaration by looking it up with DNS.  When a mailserver username is
      recognized attached to a matching hostname part, its local mapping is
      added to the list of local recipients.

      The 'checkalias' option (normally off) extends the lookups performed
      by the 'dns' keyword in multidrop mode, providing a way to cope with
      remote MTAs that identify themselves using their canonical name, while
      they're polled using an alias.  When such a server is polled, checks
      to extract the envelope address fail, and fetchmail reverts to
      delivery using the To/Cc/Bcc headers (See below 'Header vs. Envelope
      addresses').  Specifying this option instructs fetchmail to retrieve
      all the IP addresses associated with both the poll name and the name
      used by the remote MTA and to do a comparison of the IP addresses.
      This comes in handy in situations where the remote server undergoes
      frequent canonical name changes, that would otherwise require
      modifications to the rcfile.  'checkalias' has no effect if 'no dns'
      is specified in the rcfile.

      The 'aka' option is for use with multidrop mailboxes.  It allows you
      to pre-declare a list of DNS aliases for a server.  This is an
      optimization hack that allows you to trade space for speed.  When
      fetchmail, while processing a multidrop mailbox, grovels through
      message headers looking for names of the mailserver, pre-declaring
      common ones can save it from having to do DNS lookups.  Note: the
      names you give as arguments to 'aka' are matched as suffixes -- if you
      specify (say) 'aka netaxs.com', this will match not just a hostname
      netaxs.com, but any hostname that ends with '.netaxs.com'; such as
      (say) pop3.netaxs.com and mail.netaxs.com.

      The 'localdomains' option allows you to declare a list of domains
      which fetchmail should consider local.  When fetchmail is parsing
      address lines in multidrop modes, and a trailing segment of a host
      name matches a declared local domain, that address is passed through
      to the listener or MDA unaltered (local-name mappings are not
      applied).




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      If you are using 'localdomains', you may also need to specify 'no
      envelope', which disables fetchmail's normal attempt to deduce an
      envelope address from the Received line or X-Envelope-To header or
      whatever header has been previously set by 'envelope'.  If you set 'no
      envelope' in the defaults entry it is possible to undo that in
      individual entries by using 'envelope <string>'.  As a special case,
      'envelope "Received"' restores the default parsing of Received lines.

      The password option requires a string argument, which is the password
      to be used with the entry's server.

      The 'preconnect' keyword allows you to specify a shell command to be
      executed just before each time fetchmail establishes a mailserver
      connection.  This may be useful if you are attempting to set up secure
      POP connections with the aid of ssh(1).  If the command returns a
      nonzero status, the poll of that mailserver will be aborted.

      Similarly, the 'postconnect' keyword similarly allows you to specify a
      shell command to be executed just after each time a mailserver
      connection is taken down.

      The 'forcecr' option controls whether lines terminated by LF only are
      given CRLF termination before forwarding.  Strictly speaking RFC821
      requires this, but few MTAs enforce the requirement it so this option
      is normally off (only one such MTA, qmail, is in significant use at
      time of writing).

      The 'stripcr' option controls whether carriage returns are stripped
      out of retrieved mail before it is forwarded.  It is normally not
      necessary to set this, because it defaults to 'on' (CR stripping
      enabled) when there is an MDA declared but 'off' (CR stripping
      disabled) when forwarding is via SMTP.  If 'stripcr' and 'forcecr' are
      both on, 'stripcr' will override.

      The 'pass8bits' option exists to cope with Microsoft mail programs
      that stupidly slap a "Content-Transfer-Encoding: 7bit" on everything.
      With this option off (the default) and such a header present,
      fetchmail declares BODY=7BIT to an ESMTP-capable listener; this causes
      problems for messages actually using 8-bit ISO or KOI-8 character
      sets, which will be garbled by having the high bits of all characters
      stripped.  If 'pass8bits' is on, fetchmail is forced to declare
      BODY=8BITMIME to any ESMTP-capable listener.  If the listener is 8-
      bit-clean (as all the major ones now are) the right thing will
      probably result.

      The 'dropstatus' option controls whether nonempty Status and X-
      Mozilla-Status lines are retained in fetched mail (the default) or
      discarded.  Retaining them allows your MUA to see what messages (if
      any) were marked seen on the server.  On the other hand, it can



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      confuse some new-mail notifiers, which assume that anything with a
      Status line in it has been seen.  (Note: the empty Status lines
      inserted by some buggy POP servers are unconditionally discarded.)

      The 'dropdelivered' option controls whether Delivered-To headers will
      be kept in fetched mail (the default) or discarded. These headers are
      added by Qmail and Postfix mailservers in order to avoid mail loops
      but may get in your way if you try to "mirror" a mailserver within the
      same domain. Use with caution.

      The 'mimedecode' option controls whether MIME messages using the
      quoted-printable encoding are automatically converted into pure 8-bit
      data. If you are delivering mail to an ESMTP-capable, 8-bit-clean
      listener (that includes all of the major MTAs like sendmail), then
      this will automatically convert quoted-printable message headers and
      data into 8-bit data, making it easier to understand when reading
      mail. If your e-mail programs know how to deal with MIME messages,
      then this option is not needed.  The mimedecode option is off by
      default, because doing RFC2047 conversion on headers throws away
      character-set information and can lead to bad results if the encoding
      of the headers differs from the body encoding.

      The 'idle' option is intended to be used with IMAP servers supporting
      the RFC2177 IDLE command extension, but does not strictly require it.
      If it is enabled, and fetchmail detects that IDLE is supported, an
      IDLE will be issued at the end of each poll.  This will tell the IMAP
      server to hold the connection open and notify the client when new mail
      is available.  If IDLE is not supported, fetchmail will simulate it by
      periodically issuing NOOP. If you need to poll a link frequently, IDLE
      can save bandwidth by eliminating TCP/IP connects and LOGIN/LOGOUT
      sequences. On the other hand, an IDLE connection will eat almost all
      of your fetchmail's time, because it will never drop the connection
      and allow other polls to occur unless the server times out the IDLE.
      It also doesn't work with multiple folders; only the first folder will
      ever be polled.


      The 'properties' option is an extension mechanism.  It takes a string
      argument, which is ignored by fetchmail itself.  The string argument
      may be used to store configuration information for scripts which
      require it.  In particular, the output of '--configdump' option will
      make properties associated with a user entry readily available to a
      Python script.

    Miscellaneous Run Control Options
      The words 'here' and 'there' have useful English-like significance.
      Normally 'user eric is esr' would mean that mail for the remote user
      'eric' is to be delivered to 'esr', but you can make this clearer by
      saying 'user eric there is esr here', or reverse it by saying 'user



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      esr here is eric there'

      Legal protocol identifiers for use with the 'protocol' keyword are:

          auto (or AUTO) (legacy, to be removed from future release)
          pop2 (or POP2) (legacy, to be removed from future release)
          pop3 (or POP3)
          sdps (or SDPS)
          imap (or IMAP)
          apop (or APOP)
          kpop (or KPOP)


      Legal authentication types are 'any', 'password', 'kerberos',
      'kerberos_v4', 'kerberos_v5' and 'gssapi', 'cram-md5', 'otp', 'msn'
      (only for POP3), 'ntlm', 'ssh', 'external' (only IMAP).  The
      'password' type specifies authentication by normal transmission of a
      password (the password may be plain text or subject to protocol-
      specific encryption as in CRAM-MD5); 'kerberos' tells fetchmail to try
      to get a Kerberos ticket at the start of each query instead, and send
      an arbitrary string as the password; and 'gssapi' tells fetchmail to
      use GSSAPI authentication.  See the description of the 'auth' keyword
      for more.

      Specifying 'kpop' sets POP3 protocol over port 1109 with Kerberos V4
      authentication.  These defaults may be overridden by later options.

      There are some global option statements: 'set logfile' followed by a
      string sets the same global specified by --logfile.  A command-line
      --logfile option will override this. Note that --logfile is only
      effective if fetchmail detaches itself from the terminal and the
      logfile already exists before fetchmail is run, and it overrides
      --syslog in this case.  Also, 'set daemon' sets the poll interval as
      --daemon does.  This can be overridden by a command-line --daemon
      option; in particular --daemon~0 can be used to force foreground
      operation. The 'set postmaster' statement sets the address to which
      multidrop mail defaults if there are no local matches.  Finally, 'set
      syslog' sends log messages to syslogd(8).


 DEBUGGING FETCHMAIL
    Fetchmail crashing
      There are various ways in that fetchmail may "crash", i. e. stop
      operation suddenly and unexpectedly. A "crash" usually refers to an
      error condition that the software did not handle by itself. A well-
      known failure mode is the "segmentation fault" or "signal 11" or
      "SIGSEGV" or just "segfault" for short. These can be caused by
      hardware or by software problems. Software-induced segfaults can
      usually be reproduced easily and in the same place, whereas hardware-



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      induced segfaults can go away if the computer is rebooted, or powered
      off for a few hours, and can happen in random locations even if you
      use the software the same way.

      For solving hardware-induced segfaults, find the faulty component and
      repair or replace it.  may help you with details.

      For solving software-induced segfaults, the developers may need a
      "stack backtrace".


    Enabling fetchmail core dumps
      By default, fetchmail suppresses core dumps as these might contain
      passwords and other sensitive information. For debugging fetchmail
      crashes, obtaining a "stack backtrace" from a core dump is often the
      quickest way to solve the problem, and when posting your problem on a
      mailing list, the developers may ask you for a "backtrace".

      1. To get useful backtraces, fetchmail needs to be installed without
      getting stripped of its compilation symbols.  Unfortunately, most
      binary packages that are installed are stripped, and core files from
      symbol-stripped programs are worthless. So you may need to recompile
      fetchmail. On many systems, you can type

              file `which fetchmail`

      to find out if fetchmail was symbol-stripped or not. If yours was
      unstripped, fine, proceed, if it was stripped, you need to recompile
      the source code first. You do not usually need to install fetchmail in
      order to debug it.

      2. The shell environment that starts fetchmail needs to enable core
      dumps. The key is the "maximum core (file) size" that can usually be
      configured with a tool named "limit" or "ulimit". See the
      documentation for your shell for details. In the popular bash shell,
      "ulimit -Sc unlimited" will allow the core dump.

      3. You need to tell fetchmail, too, to allow core dumps. To do this,
      run fetchmail with the -d0 -v options.  It is often easier to also add
      --nosyslog -N as well.

      Finally, you need to reproduce the crash. You can just start fetchmail
      from the directory where you compiled it by typing ./fetchmail, so the
      complete command line will start with ./fetchmail -Nvd0 --nosyslog and
      perhaps list your other options.

      After the crash, run your debugger to obtain the core dump.  The
      debugger will often be GNU GDB, you can then type (adjust paths as
      necessary) gdb ./fetchmail fetchmail.core and then, after GDB has



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      started up and read all its files, type backtrace full, save the
      output (copy & paste will do, the backtrace will be read by a human)
      and then type quit to leave gdb.  Note: on some systems, the core
      files have different names, they might contain a number instead of the
      program name, or number and name, but it will usually have "core" as
      part of their name.


 INTERACTION WITH RFC 822
      When trying to determine the originating address of a message,
      fetchmail looks through headers in the following order:

              Return-Path:
              Resent-Sender: (ignored if it doesn't contain an @ or !)
              Sender: (ignored if it doesn't contain an @ or !)
              Resent-From:
              From:
              Reply-To:
              Apparently-From:

      The originating address is used for logging, and to set the MAIL FROM
      address when forwarding to SMTP.  This order is intended to cope
      gracefully with receiving mailing list messages in multidrop mode. The
      intent is that if a local address doesn't exist, the bounce message
      won't be returned blindly to the author or to the list itself, but
      rather to the list manager (which is less annoying).

      In multidrop mode, destination headers are processed as follows:
      First, fetchmail looks for the header specified by the 'envelope'
      option in order to determine the local recipient address. If the mail
      is addressed to more than one recipient, the Received line won't
      contain any information regarding recipient addresses.

      Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
      lines.  If they exist, they should contain the final recipients and
      have precedence over their To:/Cc:/Bcc: counterparts.  If the Resent-*
      lines don't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
      looked for. (The presence of a Resent-To: is taken to imply that the
      person referred by the To: address has already received the original
      copy of the mail.)


 CONFIGURATION EXAMPLES
      Note that although there are password declarations in a good many of
      the examples below, this is mainly for illustrative purposes.  We
      recommend stashing account/password pairs in your $HOME/.netrc file,
      where they can be used not just by fetchmail but by ftp(1) and other
      programs.




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      The basic format is:


           poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD


      Example:



           poll pop.provider.net protocol pop3 username "jsmith" password "secret1"


      Or, using some abbreviations:



           poll pop.provider.net proto pop3 user "jsmith" password "secret1"


      Multiple servers may be listed:



           poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
           poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"


      Here's the same version with more whitespace and some noise words:



           poll pop.provider.net proto pop3
                user "jsmith", with password secret1, is "jsmith" here;
           poll other.provider.net proto pop2:
                user "John.Smith", with password "My^Hat", is "John.Smith" here;


      If you need to include whitespace in a parameter string or start the
      latter with a number, enclose the string in double quotes.  Thus:



           poll mail.provider.net with proto pop3:
                user "jsmith" there has password "4u but u can't krak this"
                is jws here and wants mda "/bin/mail"


      You may have an initial server description headed by the keyword



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      'defaults' instead of 'poll' followed by a name.  Such a record is
      interpreted as defaults for all queries to use. It may be overwritten
      by individual server descriptions.  So, you could write:



           defaults proto pop3
                user "jsmith"
           poll pop.provider.net
                pass "secret1"
           poll mail.provider.net
                user "jjsmith" there has password "secret2"


      It's possible to specify more than one user per server.  The 'user'
      keyword leads off a user description, and every user specification in
      a multi-user entry must include it.  Here's an example:



           poll pop.provider.net proto pop3 port 3111
                user "jsmith" with pass "secret1" is "smith" here
                user jones with pass "secret2" is "jjones" here keep


      This associates the local username 'smith' with the pop.provider.net
      username 'jsmith' and the local username 'jjones' with the
      pop.provider.net username 'jones'.  Mail for 'jones' is kept on the
      server after download.


      Here's what a simple retrieval configuration for a multidrop mailbox
      looks like:



           poll pop.provider.net:
                user maildrop with pass secret1 to golux 'hurkle'='happy' snark here


      This says that the mailbox of account 'maildrop' on the server is a
      multidrop box, and that messages in it should be parsed for the server
      user names 'golux', 'hurkle', and 'snark'.  It further specifies that
      'golux' and 'snark' have the same name on the client as on the server,
      but mail for server user 'hurkle' should be delivered to client user
      'happy'.


      Note that fetchmail, until version 6.3.4, did NOT allow full



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      user@domain specifications here, these would never match.  Fetchmail
      6.3.5 and newer support user@domain specifications on the left-hand
      side of a user mapping.


      Here's an example of another kind of multidrop connection:



           poll pop.provider.net localdomains loonytoons.org toons.org
                envelope X-Envelope-To
                user maildrop with pass secret1 to * here


      This also says that the mailbox of account 'maildrop' on the server is
      a multidrop box.  It tells fetchmail that any address in the
      loonytoons.org or toons.org domains (including sub-domain addresses
      like 'joe@daffy.loonytoons.org') should be passed through to the local
      SMTP listener without modification.  Be careful of mail loops if you
      do this!


      Here's an example configuration using ssh and the plugin option.  The
      queries are made directly on the stdin and stdout of imapd via ssh.
      Note that in this setup, IMAP authentication can be skipped.



           poll mailhost.net with proto imap:
                plugin "ssh %h /usr/sbin/imapd" auth ssh;
                user esr is esr here


 THE USE AND ABUSE OF MULTIDROP
      Use the multiple-local-recipients feature with caution -- it can bite.
      All multidrop features are ineffective in ETRN and ODMR modes.

      Also, note that in multidrop mode duplicate mails are suppressed.  A
      piece of mail is considered duplicate if it has the same message-ID as
      the message immediately preceding and more than one addressee.  Such
      runs of messages may be generated when copies of a message addressed
      to multiple users are delivered to a multidrop box.


    Header vs. Envelope addresses
      The fundamental problem is that by having your mailserver toss several
      peoples' mail in a single maildrop box, you may have thrown away
      potentially vital information about who each piece of mail was
      actually addressed to (the 'envelope address', as opposed to the



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      header addresses in the RFC822 To/Cc headers - the Bcc is not
      available at the receiving end).  This 'envelope address' is the
      address you need in order to reroute mail properly.

      Sometimes fetchmail can deduce the envelope address.  If the
      mailserver MTA is sendmail and the item of mail had just one
      recipient, the MTA will have written a 'by/for' clause that gives the
      envelope addressee into its Received header. But this doesn't work
      reliably for other MTAs, nor if there is more than one recipient.  By
      default, fetchmail looks for envelope addresses in these lines; you
      can restore this default with -E "Received" or 'envelope Received'.

      As a better alternative, some SMTP listeners and/or mail servers
      insert a header in each message containing a copy of the envelope
      addresses.  This header (when it exists) is often 'X-Original-To',
      'Delivered-To' or 'X-Envelope-To'.  Fetchmail's assumption about this
      can be changed with the -E or 'envelope' option.  Note that writing an
      envelope header of this kind exposes the names of recipients
      (including blind-copy recipients) to all receivers of the messages, so
      the upstream must store one copy of the message per recipient to avoid
      becoming a privacy problem.

      Postfix, since version 2.0, writes an X-Original-To: header which
      contains a copy of the envelope as it was received.

      Qmail and Postfix generally write a 'Delivered-To' header upon
      delivering the message to the mail spool and use it to avoid mail
      loops.  Qmail virtual domains however will prefix the user name with a
      string that normally matches the user's domain. To remove this prefix
      you can use the -Q or 'qvirtual' option.

      Sometimes, unfortunately, neither of these methods works.  That is the
      point when you should contact your ISP and ask them to provide such an
      envelope header, and you should not use multidrop in this situation.
      When they all fail, fetchmail must fall back on the contents of To/Cc
      headers (Bcc headers are not available - see below) to try to
      determine recipient addressees -- and these are unreliable.  In
      particular, mailing-list software often ships mail with only the list
      broadcast address in the To header.

      Note that a future version of fetchmail may remove To/Cc parsing!

      When fetchmail cannot deduce a recipient address that is local, and
      the intended recipient address was anyone other than fetchmail's
      invoking user, mail will get lost.  This is what makes the multidrop
      feature risky without proper envelope information.

      A related problem is that when you blind-copy a mail message, the Bcc
      information is carried only as envelope address (it's removed from the



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      headers by the sending mail server, so fetchmail can see it only if
      there is an X-Envelope-To header).  Thus, blind-copying to someone who
      gets mail over a fetchmail multidrop link will fail unless the the
      mailserver host routinely writes X-Envelope-To or an equivalent header
      into messages in your maildrop.

      In conclusion, mailing lists and Bcc'd mail can only work if the
      server you're fetching from

      (1)  stores one copy of the message per recipient in your domain and

      (2)  records the envelope information in a special header
           (X-Original-To, Delivered-To, X-Envelope-To).


    Good Ways To Use Multidrop Mailboxes
      Multiple local names can be used to administer a mailing list from the
      client side of a fetchmail collection.  Suppose your name is 'esr',
      and you want to both pick up your own mail and maintain a mailing list
      called (say) "fetchmail-friends", and you want to keep the alias list
      on your client machine.

      On your server, you can alias 'fetchmail-friends' to 'esr'; then, in
      your .fetchmailrc, declare 'to esr fetchmail-friends here'.  Then,
      when mail including 'fetchmail-friends' as a local address gets
      fetched, the list name will be appended to the list of recipients your
      SMTP listener sees.  Therefore it will undergo alias expansion
      locally.  Be sure to include 'esr' in the local alias expansion of
      fetchmail-friends, or you'll never see mail sent only to the list.
      Also be sure that your listener has the "me-too" option set
      (sendmail's -oXm command-line option or OXm declaration) so your name
      isn't removed from alias expansions in messages you send.

      This trick is not without its problems, however.  You'll begin to see
      this when a message comes in that is addressed only to a mailing list
      you do not have declared as a local name.  Each such message will
      feature an 'X-Fetchmail-Warning' header which is generated because
      fetchmail cannot find a valid local name in the recipient addresses.
      Such messages default (as was described above) to being sent to the
      local user running fetchmail, but the program has no way to know that
      that's actually the right thing.


    Bad Ways To Abuse Multidrop Mailboxes
      Multidrop mailboxes and fetchmail serving multiple users in daemon
      mode do not mix.  The problem, again, is mail from mailing lists,
      which typically does not have an individual recipient address on it.
      Unless fetchmail can deduce an envelope address, such mail will only
      go to the account running fetchmail (probably root).  Also, blind-



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      copied users are very likely never to see their mail at all.

      If you're tempted to use fetchmail to retrieve mail for multiple users
      from a single mail drop via POP or IMAP, think again (and reread the
      section on header and envelope addresses above).  It would be smarter
      to just let the mail sit in the mailserver's queue and use fetchmail's
      ETRN or ODMR modes to trigger SMTP sends periodically (of course, this
      means you have to poll more frequently than the mailserver's expiry
      period).  If you can't arrange this, try setting up a UUCP feed.

      If you absolutely must use multidrop for this purpose, make sure your
      mailserver writes an envelope-address header that fetchmail can see.
      Otherwise you will lose mail and it will come back to haunt you.


    Speeding Up Multidrop Checking
      Normally, when multiple users are declared fetchmail extracts
      recipient addresses as described above and checks each host part with
      DNS to see if it's an alias of the mailserver.  If so, the name
      mappings described in the "to ... here" declaration are done and the
      mail locally delivered.

      This is a convenient but also slow method.  To speed it up, pre-
      declare mailserver aliases with 'aka'; these are checked before DNS
      lookups are done.  If you're certain your aka list contains all DNS
      aliases of the mailserver (and all MX names pointing at it - note this
      may change in a future version) you can declare 'no dns' to suppress
      DNS lookups entirely and only match against the aka list.


 SOCKS
      Support for socks4/5 is a compile time configuration option. Once
      compiled in, fetchmail will always use the socks libraries and
      configuration on your system, there are no run-time switches in
      fetchmail - but you can still configure SOCKS: you can specify which
      SOCKS configuration file is used in the SOCKS_CONF environment
      variable.

      For instance, if you wanted to bypass the SOCKS proxy altogether and
      have fetchmail connect directly, you could just pass
      SOCKS_CONF=/dev/null in the environment, for example (add your usual
      command line options - if any - to the end of this line):

      env SOCKS_CONF=/dev/null fetchmail


 EXIT CODES
      To facilitate the use of fetchmail in shell scripts, an exit status
      code is returned to give an indication of what occurred during a given



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      connection.

      The exit codes returned by fetchmail are as follows:

      0    One or more messages were successfully retrieved (or, if the -c
           option was selected, were found waiting but not retrieved).

      1    There was no mail awaiting retrieval.  (There may have been old
           mail still on the server but not selected for retrieval.) If you
           do not want "no mail" to be an error condition (for instance, for
           cron jobs), use a POSIX-compliant shell and add

           || [ $? -eq 1 ]

           to the end of the fetchmail command line, note that this leaves 0
           untouched, maps 1 to 0, and maps all other codes to 1. See also
           item #C8 in the FAQ.

      2    An error was encountered when attempting to open a socket to
           retrieve mail.  If you don't know what a socket is, don't worry
           about it -- just treat this as an 'unrecoverable error'.  This
           error can also be because a protocol fetchmail wants to use is
           not listed in /etc/services.

      3    The user authentication step failed.  This usually means that a
           bad user-id, password, or APOP id was specified.  Or it may mean
           that you tried to run fetchmail under circumstances where it did
           not have standard input attached to a terminal and could not
           prompt for a missing password.

      4    Some sort of fatal protocol error was detected.

      5    There was a syntax error in the arguments to fetchmail, or a pre-
           or post-connect command failed.

      6    The run control file had bad permissions.

      7    There was an error condition reported by the server.  Can also
           fire if fetchmail timed out while waiting for the server.

      8    Client-side exclusion error.  This means fetchmail either found
           another copy of itself already running, or failed in such a way
           that it isn't sure whether another copy is running.

      9    The user authentication step failed because the server responded
           "lock busy".  Try again after a brief pause!  This error is not
           implemented for all protocols, nor for all servers.  If not
           implemented for your server, "3" will be returned instead, see
           above.  May be returned when talking to qpopper or other servers



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           that can respond with "lock busy" or some similar text containing
           the word "lock".

      10   The fetchmail run failed while trying to do an SMTP port open or
           transaction.

      11   Fatal DNS error.  Fetchmail encountered an error while performing
           a DNS lookup at startup and could not proceed.

      12   BSMTP batch file could not be opened.

      13   Poll terminated by a fetch limit (see the --fetchlimit option).

      14   Server busy indication.

      23   Internal error.  You should see a message on standard error with
           details.

      24 - 26, 28, 29
           These are internal codes and should not appear externally.

      When fetchmail queries more than one host, return status is 0 if any
      query successfully retrieved mail. Otherwise the returned error status
      is that of the last host queried.


 FILES
      ~/.fetchmailrc
           default run control file

      ~/.fetchids
           default location of file recording last message UIDs seen per
           host.

      ~/.fetchmail.pid
           lock file to help prevent concurrent runs (non-root mode).

      ~/.netrc
           your FTP run control file, which (if present) will be searched
           for passwords as a last resort before prompting for one
           interactively.

      /var/run/fetchmail.pid
           lock file to help prevent concurrent runs (root mode, Linux
           systems).

      /etc/fetchmail.pid
           lock file to help prevent concurrent runs (root mode, systems
           without /var/run).



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 ENVIRONMENT
      FETCHMAILHOME
           If this environment variable is set to a valid and existing
           directory name, fetchmail will read $FETCHMAILHOME/fetchmailrc
           (the dot is missing in this case), $FETCHMAILHOME/.fetchids and
           $FETCHMAILHOME/.fetchmail.pid rather than from the user's home
           directory.  The .netrc file is always looked for in the the
           invoking user's home directory regardless of FETCHMAILHOME's
           setting.


      FETCHMAILUSER
           If this environment variable is set, it is used as the name of
           the calling user (default local name) for purposes such as
           mailing error notifications.  Otherwise, if either the LOGNAME or
           USER variable is correctly set (e.g. the corresponding UID
           matches the session user ID) then that name is used as the
           default local name.  Otherwise getpwuid(3) must be able to
           retrieve a password entry for the session ID (this elaborate
           logic is designed to handle the case of multiple names per userid
           gracefully).


      FETCHMAIL_DISABLE_CBC_IV_COUNTERMEASURE
           (since v6.3.22): If this environment variable is set and not
           empty, fetchmail will disable a countermeasure against an SSL CBC
           IV attack (by setting SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS).  This
           is a security risk, but may be necessary for connecting to
           certain non-standards-conforming servers.  See fetchmail's NEWS
           file and fetchmail-SA-2012-01.txt for details.  Earlier fetchmail
           versions (v6.3.21 and older) used to disable this countermeasure,
           but v6.3.22 no longer does that as a safety precaution.


      FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS
           (since v6.3.17): If this environment variable is set and not
           empty, fetchmail will always load the default X.509 trusted
           certificate locations for SSL/TLS CA certificates, even if
           --sslcertfile and --sslcertpath are given.  The latter locations
           take precedence over the system default locations.  This is
           useful in case there are broken certificates in the system
           directories and the user has no administrator privileges to
           remedy the problem.


      HOME_ETC
           If the HOME_ETC variable is set, fetchmail will read
           $HOME_ETC/.fetchmailrc instead of ~/.fetchmailrc.




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           If HOME_ETC and FETCHMAILHOME are both set, HOME_ETC will be
           ignored.


      SOCKS_CONF
           (only if SOCKS support is compiled in) this variable is used by
           the socks library to find out which configuration file it should
           read. Set this to /dev/null to bypass the SOCKS proxy.


 SIGNALS
      If a fetchmail daemon is running as root, SIGUSR1 wakes it up from its
      sleep phase and forces a poll of all non-skipped servers. For
      compatibility reasons, SIGHUP can also be used in 6.3.X but may not be
      available in future fetchmail versions.

      If fetchmail is running in daemon mode as non-root, use SIGUSR1 to
      wake it (this is so SIGHUP due to logout can retain the default action
      of killing it).

      Running fetchmail in foreground while a background fetchmail is
      running will do whichever of these is appropriate to wake it up.


 BUGS, LIMITATIONS, AND KNOWN PROBLEMS
      Please check the NEWS file that shipped with fetchmail for more known
      bugs than those listed here.

      Fetchmail cannot handle user names that contain blanks after a "@"
      character, for instance "demonstr@ti on". These are rather uncommon
      and only hurt when using UID-based --keep setups, so the 6.3.X
      versions of fetchmail won't be fixed.

      Fetchmail cannot handle configurations where you have multiple
      accounts that use the same server name and the same login. Any
      user@server combination must be unique.

      The assumptions that the DNS and in particular the checkalias options
      make are not often sustainable. For instance, it has become uncommon
      for an MX server to be a POP3 or IMAP server at the same time.
      Therefore the MX lookups may go away in a future release.

      The mda and plugin options interact badly.  In order to collect error
      status from the MDA, fetchmail has to change its normal signal
      handling so that dead plugin processes don't get reaped until the end
      of the poll cycle.  This can cause resource starvation if too many
      zombies accumulate.  So either don't deliver to a MDA using plugins or
      risk being overrun by an army of undead.




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      The --interface option does not support IPv6 and it is doubtful if it
      ever will, since there is no portable way to query interface IPv6
      addresses.

      The RFC822 address parser used in multidrop mode chokes on some @-
      addresses that are technically legal but bizarre.  Strange uses of
      quoting and embedded comments are likely to confuse it.

      In a message with multiple envelope headers, only the last one
      processed will be visible to fetchmail.

      Use of some of these protocols requires that the program send
      unencrypted passwords over the TCP/IP connection to the mailserver.
      This creates a risk that name/password pairs might be snaffled with a
      packet sniffer or more sophisticated monitoring software.  Under Linux
      and FreeBSD, the --interface option can be used to restrict polling to
      availability of a specific interface device with a specific local or
      remote IP address, but snooping is still possible if (a) either host
      has a network device that can be opened in promiscuous mode, or (b)
      the intervening network link can be tapped.  We recommend the use of
      ssh(1) tunnelling to not only shroud your passwords but encrypt the
      entire conversation.

      Use of the %F or %T escapes in an mda option could open a security
      hole, because they pass text manipulable by an attacker to a shell
      command.  Potential shell characters are replaced by '_' before
      execution.  The hole is further reduced by the fact that fetchmail
      temporarily discards any suid privileges it may have while running the
      MDA.  For maximum safety, however, don't use an mda command containing
      %F or %T when fetchmail is run from the root account itself.

      Fetchmail's method of sending bounces due to errors or spam-blocking
      and spam bounces requires that port 25 of localhost be available for
      sending mail via SMTP.

      If you modify ~/.fetchmailrc while a background instance is running
      and break the syntax, the background instance will die silently.
      Unfortunately, it can't die noisily because we don't yet know whether
      syslog should be enabled.  On some systems, fetchmail dies quietly
      even if there is no syntax error; this seems to have something to do
      with buggy terminal ioctl code in the kernel.

      The -f~- option (reading a configuration from stdin) is incompatible
      with the plugin option.

      The 'principal' option only handles Kerberos IV, not V.

      Interactively entered passwords are truncated after 63 characters. If
      you really need to use a longer password, you will have to use a



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      configuration file.

      A backslash as the last character of a configuration file will be
      flagged as a syntax error rather than ignored.

      The BSMTP error handling is virtually nonexistent and may leave broken
      messages behind.

      Send comments, bug reports, gripes, and the like to the


      An is available at the fetchmail home page, it should also accompany
      your installation.


 AUTHOR
      Fetchmail is currently maintained by Matthias Andree and Rob Funk with
      major assistance from Sunil Shetye (for code) and Rob MacGregor (for
      the mailing lists).

      Most of the code is from .  Too many other people to name here have
      contributed code and patches.

      This program is descended from and replaces popclient, by ; the
      internals have become quite different, but some of its interface
      design is directly traceable to that ancestral program.

      This manual page has been improved by Matthias Andree, R. Hannes
      Beinert, and H['e]ctor Garc['i]a.


 SEE ALSO
      README, README.SSL, README.SSL-SERVER, mutt(1), elm(1), mail(1),
      sendmail(8), popd(8), imapd(8), netrc(5).


 APPLICABLE STANDARDS
      Note that this list is just a collection of references and not a
      statement as to the actual protocol conformance or requirements in
      fetchmail.

      SMTP/ESMTP:
           RFC 821, RFC 2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC
           1985, RFC 2554.

      mail:
           RFC 822, RFC 2822, RFC 1123, RFC 1892, RFC 1894.

      POP2:



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           RFC 937

      POP3:
           RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC 1734, RFC 1939, RFC
           1957, RFC 2195, RFC 2449.

      APOP:
           RFC 1939.

      RPOP:
           RFC 1081, RFC 1225.

      IMAP2/IMAP2BIS:
           RFC 1176, RFC 1732.

      IMAP4/IMAP4rev1:
           RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC
           2177, RFC 2683.

      ETRN:
           RFC 1985.

      ODMR/ATRN:
           RFC 2645.

      OTP: RFC 1938.

      LMTP:
           RFC 2033.

      GSSAPI:
           RFC 1508, RFC 1734,

      TLS: RFC 2595.


















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