2 .\" ** The above line should force tbl to be used as a preprocessor **
4 .\" Manual page in man(7) format with tbl(1) macros for fetchmail
6 .\" For license terms, see the file COPYING in this directory.
10 fetchmail \- fetch mail from a POP, IMAP, ETRN, or ODMR-capable server
13 \fBfetchmail\fR [\fIoption...\fR] [\fImailserver...\fR]
19 is a mail-retrieval and forwarding utility; it fetches mail from
20 remote mailservers and forwards it to your local (client) machine's
21 delivery system. You can then handle the retrieved mail using normal
22 mail user agents such as \fImutt\fR(1), \fIelm\fR(1) or \fIMail\fR(1).
23 The \fIfetchmail\fR utility can be run in a daemon mode to repeatedly
24 poll one or more systems at a specified interval.
28 program can gather mail from servers supporting any of the common
29 mail-retrieval protocols: POP2 (legacy, to be removed from future
30 release), POP3, IMAP2bis, IMAP4, and IMAP4rev1.
31 It can also use the ESMTP ETRN extension and ODMR. (The RFCs describing all
32 these protocols are listed at the end of this manual page.)
36 is primarily intended to be used over on-demand TCP/IP links (such as
37 SLIP or PPP connections), it may also be useful as a message transfer
38 agent for sites which refuse for security reasons to permit
39 (sender-initiated) SMTP transactions with sendmail.
43 is used with a POP or an IMAP server, it has two fundamental modes of
44 operation for each user account from which it retrieves mail:
45 \fIsingledrop\fR- and \fImultidrop\fR-mode. In singledrop-mode,
47 assumes that all messages in the user's account are intended for a single
48 recipient. An individual mail message will not be inspected for recipient
49 information, rather, the identity of the recipient will either default to
50 the local user currently executing \fIfetchmail\fR,
51 or else will need to be explicitly specified in the configuration file.
52 Singledrop-mode is used when the fetchmailrc configuration contains at
53 most a single local user specification for a given server account.
57 is not able to assume that there is only a single recipient, but rather
58 that the mail server account actually contains mail intended for any
59 number of different recipients. Therefore,
61 must attempt to deduce the proper "envelope recipient" from the mail
62 headers of each message. In this mode of operation
64 almost resembles an MTA, however it is important to note that neither
65 the POP nor IMAP protocols were intended for use in this fashion, and
66 hence envelope information is not directly available. Instead,
68 must resort to a process of informed guess-work in an attempt to
69 discover the true envelope recipient of a message. Even if this
70 information is present in the headers, the process can
71 be error-prone and is dependent upon the specific mail server used
72 for mail retrieval. Multidrop-mode is used when more than one local
73 user is specified for a particular server account in the configuration
74 file. Note that the forgoing discussion of singledrop- and
75 multidrop-modes does not apply to the ESMTP ETRN or ODMR retrieval
76 methods, since they are based upon the SMTP protocol which
77 specifically provides the envelope recipient to \fIfetchmail\fR.
79 As each message is retrieved \fIfetchmail\fR normally delivers it via SMTP to
80 port 25 on the machine it is running on (localhost), just as though it
81 were being passed in over a normal TCP/IP link. \fIfetchmail\fR provides
82 the SMTP server with an envelope recipient derived in the manner described
83 previously. The mail will then be
84 delivered locally via your system's MDA (Mail Delivery Agent, usually
85 \fIsendmail\fR(8) but your system may use a different one such
86 as \fIsmail\fR, \fImmdf\fR, \fIexim\fR, \fIpostfix\fR, or \fIqmail\fR). All the
87 delivery-control mechanisms (such as \fI.forward\fR files) normally
88 available through your system MDA and local delivery agents will
89 therefore work automatically.
91 If no port 25 listener is available, but your fetchmail configuration
92 was told about a reliable local MDA, it will use that MDA for local
97 is available, it will assist you in setting up and editing a
98 fetchmailrc configuration. It runs under the X window system and
99 requires that the language Python and the Tk toolkit be present on your
100 system. If you are first setting up fetchmail for single-user mode, it
101 is recommended that you use Novice mode. Expert mode provides complete
102 control of fetchmail configuration, including the multidrop features.
103 In either case, the 'Autoprobe' button will tell you the most capable
104 protocol a given mailserver supports, and warn you of potential problems
107 .SH GENERAL OPERATION
110 is controlled by command-line options and a run control file,
111 .IR ~/.fetchmailrc\fR ,
112 the syntax of which we describe in a later section (this file is what
113 the \fIfetchmailconf\fR program edits). Command-line options override
117 Each server name that you specify following the options on the
118 command line will be queried. If you don't specify any servers
119 on the command line, each 'poll' entry in your
121 file will be queried.
123 To facilitate the use of
125 in scripts and pipelines, it returns an appropriate exit code upon
126 termination -- see EXIT CODES below.
128 The following options modify the behavior of \fIfetchmail\fR. It is
129 seldom necessary to specify any of these once you have a
130 working \fI.fetchmailrc\fR file set up.
132 Almost all options have a corresponding keyword which can be used to
137 Some special options are not covered here, but are documented instead
138 in sections on AUTHENTICATION and DAEMON MODE which follow.
142 Displays the version information for your copy of
144 No mail fetch is performed.
145 Instead, for each server specified, all the option information
146 that would be computed if
148 were connecting to that server is displayed. Any non-printables in
149 passwords or other string names are shown as backslashed C-like
150 escape sequences. This option is useful for verifying that your
151 options are set the way you want them.
154 Return a status code to indicate whether there is mail waiting,
155 without actually fetching or deleting mail (see EXIT CODES below).
156 This option turns off daemon mode (in which it would be useless). It
157 doesn't play well with queries to multiple sites, and doesn't work
158 with ETRN or ODMR. It will return a false positive if you leave read but
159 undeleted mail in your server mailbox and your fetch protocol can't
160 tell kept messages from new ones. This means it will work with IMAP,
161 not work with POP2, and may occasionally flake out under POP3.
164 Silent mode. Suppresses all progress/status messages that are
165 normally echoed to standard output during a fetch (but does not
166 suppress actual error messages). The \-\-verbose option overrides this.
169 Verbose mode. All control messages passed between
171 and the mailserver are echoed to stdout. Overrides \-\-silent.
172 Doubling this option (\-v \-v) causes extra diagnostic information
178 Retrieve both old (seen) and new messages from the mailserver. The
179 default is to fetch only messages the server has not marked seen.
180 Under POP3, this option also forces the use of RETR rather than TOP.
181 Note that POP2 retrieval behaves as though \-\-all is always on (see
182 RETRIEVAL FAILURE MODES below) and this option does not work with ETRN
187 Keep retrieved messages on the remote mailserver. Normally, messages
188 are deleted from the folder on the mailserver after they have been retrieved.
191 option causes retrieved messages to remain in your folder on the
192 mailserver. This option does not work with ETRN or ODMR.
196 Delete retrieved messages from the remote mailserver. This
197 option forces retrieved mail to be deleted. It may be useful if
198 you have specified a default of \fBkeep\fR in your
199 \&\fI.fetchmailrc\fR. This option is forced on with ETRN and ODMR.
202 POP3/IMAP only. This is a dangerous option and can cause mail loss when
203 used improperly. It deletes old (seen) messages from the mailserver
204 before retrieving new messages. Warning: This can cause mail loss if
205 you check your mail with other clients than fetchmail, and cause
206 fetchmail to delete a message it had never fetched before. Similarly, if
207 your local MTA hangs and fetchmail is aborted, the next time you run
208 fetchmail, it will delete mail that was never delivered to you. You
209 should probably not use this option in your configuration file. What you
210 probably want is the default setting: if you don't specify '\-k', then
211 fetchmail will automatically delete messages after successful
212 delivery. This option does not work with ETRN and ODMR.
215 POP3/IMAP only, since version 6.3.0. Delete oversized messages from the
216 mailserver before retrieving new messages. The size limit should be
217 separately specified with the \-\-limit option. This option does not
218 work with ETRN or ODMR.
219 .SS Protocol and Query Options
221 .B \-p <proto> | \-\-proto <proto> | \-\-protocol <proto>
222 (Keyword: proto[col])
223 Specify the protocol to use when communicating with the remote
224 mailserver. If no protocol is specified, the default is AUTO.
226 may be one of the following:
229 Tries IMAP, POP3, and POP2 (skipping any of these for which support
230 has not been compiled in).
232 Post Office Protocol 2 (legacy, to be removed from future release)
234 Post Office Protocol 3
236 Use POP3 with old-fashioned MD5-challenge authentication.
238 Use POP3 with RPOP authentication.
240 Use POP3 with Kerberos V4 authentication on port 1109.
242 Use POP3 with Demon Internet's SDPS extensions.
244 IMAP2bis, IMAP4, or IMAP4rev1 (\fIfetchmail\fR automatically detects their capabilities).
246 Use the ESMTP ETRN option.
248 Use the the On-Demand Mail Relay ESMTP profile.
251 All these alternatives work in basically the same way (communicating
252 with standard server daemons to fetch mail already delivered to a
253 mailbox on the server) except ETRN and ODMR. The ETRN mode
254 allows you to ask a compliant ESMTP server (such as BSD sendmail at
255 release 8.8.0 or higher) to immediately open a sender-SMTP connection
256 to your client machine and begin forwarding any items addressed to
257 your client machine in the server's queue of undelivered mail. The
258 ODMR mode requires an ODMR-capable server and works similarly to
259 ETRN, except that it does not require the client machine to have
264 Force UIDL use (effective only with POP3). Force client-side tracking
265 of 'newness' of messages (UIDL stands for "unique ID listing" and is
266 described in RFC1939). Use with 'keep' to use a mailbox as a baby
267 news drop for a group of users. The fact that seen messages are skipped
268 is logged, unless error logging is done through syslog while running in
269 daemon mode. Note that fetchmail may automatically enable this option
270 depending on upstream server capabilities. Note also that this option
271 may be removed and forced enabled in a future fetchmail version.
274 .B \-P <portnumber> | \-\-service <servicename>
275 (Keyword: service) Since version 6.3.0.
276 The service option permits you to specify a service name to connect to.
277 You can specify a decimal port number here, if your services database
278 lacks the required service-port assignments. See the FAQ item R12 and
279 the \-\-ssl documentation for details. This replaces the older \-\-port
282 .B \-\-port <portnumber>
284 Obsolete version of \-\-service that does not take service names.
286 this option may be removed from a future version.
288 .B \-\-principal <principal>
290 The principal option permits you to specify a service principal for
291 mutual authentication. This is applicable to POP3 or IMAP with Kerberos
294 .B \-t <seconds> | \-\-timeout <seconds>
296 The timeout option allows you to set a server-nonresponse
297 timeout in seconds. If a mailserver does not send a greeting message
298 or respond to commands for the given number of seconds,
299 \fIfetchmail\fR will hang up on it. Without such a timeout
300 \fIfetchmail\fR might hang up indefinitely trying to fetch mail from a
301 down host. This would be particularly annoying for a \fIfetchmail\fR
302 running in background. There is a default timeout which fetchmail\~\-V
303 will report. If a given connection receives too many timeouts in
304 succession, fetchmail will consider it wedged and stop retrying,
305 the calling user will be notified by email if this happens.
307 .B \-\-plugin <command>
308 (Keyword: plugin) The plugin option allows you to use an external
309 program to establish the TCP connection. This is useful if you want
310 to use socks, SSL, ssh, or need some special firewalling setup. The
311 program will be looked up in $PATH and can optionally be passed the
312 hostname and port as arguments using "%h" and "%p" respectively (note
313 that the interpolation logic is rather primitive, and these token must
314 be bounded by whitespace or beginning of string or end of string).
315 Fetchmail will write to the plugin's stdin and read from the plugin's
318 .B \-\-plugout <command>
320 Identical to the plugin option above, but this one is used for the SMTP
321 connections (which will probably not need it, so it has been separated
324 .B \-r <name> | \-\-folder <name>
326 Causes a specified non-default mail folder on the mailserver (or
327 comma-separated list of folders) to be retrieved. The syntax of the
328 folder name is server-dependent. This option is not available under
332 (Keyword: tracepolls)
333 Tell fetchmail to poll trace information in the form 'polling %s
334 account %s' to the Received line it generates, where the %s parts are
335 replaced by the user's remote name and the poll label (the Received
336 header also normally includes the server's true name). This can be
337 used to facilitate mail filtering based on the account it is being
342 Causes the connection to the mail server to be encrypted via SSL. Connect
343 to the server using the specified base protocol over a connection secured
344 by SSL. SSL support must be present at the server.
346 Note that fetchmail may still try to negotiate TLS even if this option
347 is not given. You can use the \-\-sslproto option to defeat this
348 behavior or tell fetchmail to negotiate a particular SSL protocol.
350 If no port is specified, the connection is attempted to the well known
351 port of the SSL version of the base protocol. This is generally a
352 different port than the port used by the base protocol. For IMAP, this
353 is port 143 for the clear protocol and port 993 for the SSL secured
354 protocol, for POP3, it is port 110 for the clear text and port 995 for
355 the encrypted variant.
357 If your system lacks the corresponding entries from /etc/services, see
358 the \-\-service option and specify the numeric port number as given in
359 the previous paragraph (unless your ISP had directed you to different
360 ports, which is uncommon however).
362 .B \-\-sslcert <name>
364 Specifies the file name of the client side public SSL certificate. Some
365 SSL encrypted servers may require client side keys and certificates for
366 authentication. In most cases, this is optional. This specifies
367 the location of the public key certificate to be presented to the server
368 at the time the SSL session is established. It is not required (but may
369 be provided) if the server does not require it. Some servers may
370 require it, some servers may request it but not require it, and some
371 servers may not request it at all. It may be the same file
372 as the private key (combined key and certificate file) but this is not
377 Specifies the file name of the client side private SSL key. Some SSL
378 encrypted servers may require client side keys and certificates for
379 authentication. In most cases, this is optional. This specifies
380 the location of the private key used to sign transactions with the server
381 at the time the SSL session is established. It is not required (but may
382 be provided) if the server does not require it. Some servers may
383 require it, some servers may request it but not require it, and some
384 servers may not request it at all. It may be the same file
385 as the public key (combined key and certificate file) but this is not
386 recommended. If a password is required to unlock the key, it will be
387 prompted for at the time just prior to establishing the session to the
388 server. This can cause some complications in daemon mode.
390 .B \-\-sslproto <name>
392 Forces an SSL protocol. Possible values are '\fBssl2\fR',
393 \&'\fBssl3\fR', '\fBssl23\fR', and '\fBtls1\fR'. Try this if the default
394 handshake does not work for your server. To defeat automatic TLSv1
395 negotiation when the server advertises STARTTLS or STLS, use \fB''\fR or
396 \&'\fBssl23\fR'. The default is to try appropriate protocols depending
401 Causes fetchmail to strictly check the server certificate against a set of
402 local trusted certificates (see the \fBsslcertpath\fR option). If the server
403 certificate is not signed by one of the trusted ones (directly or indirectly),
404 the SSL connection will fail. This checking should prevent man-in-the-middle
405 attacks against the SSL connection. Note that CRLs are seemingly not currently
406 supported by OpenSSL in certificate verification! Your system clock should
407 be reasonably accurate when using this option!
409 .B \-\-sslcertpath <directory>
410 (Keyword: sslcertpath)
411 Sets the directory fetchmail uses to look up local certificates. The default
412 is your OpenSSL default one. The directory must be hashed as OpenSSL expects
413 it - every time you add or modify a certificate in the directory, you need
414 to use the \fBc_rehash\fR tool (which comes with OpenSSL in the tools/
417 .B \-\-sslfingerprint <fingerprint>
418 (Keyword: sslfingerprint)
419 Specify the fingerprint of the server key (an MD5 hash of the key) in
420 hexadecimal notation with colons separating groups of two digits. The letter
421 hex digits must be in upper case. This is the default format OpenSSL uses,
422 and the one fetchmail uses to report the fingerprint when an SSL connection
423 is established. When this is specified, fetchmail will compare the server key
424 fingerprint with the given one, and the connection will fail if they do not
425 match. This can be used to prevent man-in-the-middle attacks.
427 To obtain the fingerprint of a certificate stored in the file cert.pem,
431 openssl x509 \-in cert.pem \-noout \-fingerprint
436 .SS Delivery Control Options
438 .B \-S <hosts> | \-\-smtphost <hosts>
439 (Keyword: smtp[host])
440 Specify a hunt list of hosts to forward mail to (one or more
441 hostnames, comma-separated). Hosts are tried in list order; the first
442 one that is up becomes the forwarding target for the current run. If
443 this option is not specified, 'localhost' is used as the default.
444 Each hostname may have a port number following the host name. The
445 port number is separated from the host name by a slash; the default
446 port is "smtp". If you specify an absolute path name (beginning with
447 a /), it will be interpreted as the name of a UNIX socket accepting
448 LMTP connections (such as is supported by the Cyrus IMAP daemon)
452 \-\-smtphost server1,server2/2525,server3,/var/imap/socket/lmtp
455 This option can be used with ODMR, and will make fetchmail a relay
456 between the ODMR server and SMTP or LMTP receiver.
458 .B \-\-fetchdomains <hosts>
459 (Keyword: fetchdomains)
460 In ETRN or ODMR mode, this option specifies the list of domains the
461 server should ship mail for once the connection is turned around. The
462 default is the FQDN of the machine running
465 .B \-D <domain> | \-\-smtpaddress <domain>
466 (Keyword: smtpaddress) Specify the domain to be appended to addresses
467 in RCPT TO lines shipped to SMTP. When this is not specified, the name
468 of the SMTP server (as specified by \-\-smtphost) is used for SMTP/LMTP
469 and 'localhost' is used for UNIX socket/BSMTP.
471 .B \-\-smtpname <user@domain>
473 Specify the domain and user to be put in RCPT TO lines shipped to SMTP.
474 The default user is the current local user.
476 .B \-Z <nnn> | \-\-antispam <nnn[, nnn]...>
478 Specifies the list of numeric SMTP errors that are to be interpreted
479 as a spam-block response from the listener. A value of \-1 disables
480 this option. For the command-line option, the list values should
483 .B \-m <command> | \-\-mda <command>
484 (Keyword: mda) You can force mail to be passed to an MDA directly
485 (rather than forwarded to port 25) with the \-\-mda or \-m option. To
486 avoid losing mail, use this option only with MDAs like maildrop or
487 MTAs like sendmail that return a nonzero status on disk-full and other
488 resource-exhaustion errors; the nonzero status tells fetchmail that
489 delivery failed and prevents the message from being deleted off the
490 server. If \fIfetchmail\fR is running as root, it sets its user id to
491 that of the target user while delivering mail through an MDA. Some
492 possible MDAs are "/usr/sbin/sendmail \-i \-f %F %T", "/usr/bin/deliver"
493 and "/usr/bin/maildrop \-d %T". Local delivery
494 addresses will be inserted into the MDA command wherever you place a
495 %T; the mail message's From address will be inserted where you place
496 an %F. \fBDO NOT ENCLOSE THE %F OR %T STRING IN SINGLE QUOTES!\fR For
497 both %T and %F, fetchmail encloses the addresses in single quotes ('),
498 after removing any single quotes they may contain, before the MDA
499 command is passed to the shell. Do \fINOT\fR use an MDA invocation
500 like "sendmail \-i \-t" that dispatches on the contents of To/Cc/Bcc, it
501 will create mail loops and bring the just wrath of many postmasters
502 down upon your head. Also, do \fInot\fR try to combine multidrop
503 mode with an MDA such as maildrop or procmail that can only accept one
504 address; you will lose mail.
506 A word of warning: the well-known
508 package is very hard to configure properly, it has a very nasty "fall
509 through to the next rule" behavior on delivery errors (even temporary
510 ones, such as out of disk space if another user's mail daemon copies the
511 mailbox around to purge old messages), so your mail will end up in the
512 wrong mailbox sooner or later. The proper procmail configuration is
513 outside the scope of this document though. Using
515 is usually much easier, and many users find the filter syntax used by
516 maildrop easier to understand.
521 Cause delivery via LMTP (Local Mail Transfer Protocol). A service
522 host and port \fBmust\fR be explicitly specified on each host in the
523 smtphost hunt list (see above) if this option is selected; the default
524 port 25 will (in accordance with RFC 2033) not be accepted.
526 .B \-\-bsmtp <filename>
528 Append fetched mail to a BSMTP file. This simply contains the SMTP
529 commands that would normally be generated by fetchmail when passing
530 mail to an SMTP listener daemon. An argument of '\-' causes the mail
531 to be written to standard output. Note that fetchmail's
532 reconstruction of MAIL FROM and RCPT TO lines is not guaranteed
533 correct; the caveats discussed under THE USE AND ABUSE OF MULTIDROP
534 MAILBOXES below apply.
535 .SS Resource Limit Control Options
537 .B \-l <maxbytes> | \-\-limit <maxbytes>
538 (Keyword: limit) Takes a maximum octet size argument. Messages larger
539 than this size will not be fetched and will be left on the server (in
540 foreground sessions, the progress messages will note that they are
541 "oversized"). If the fetch protocol permits (in particular, under
542 IMAP or POP3 without the fetchall option) the message will not be
545 An explicit \-\-limit of 0 overrides any limits set in your
546 run control file. This option is intended for those needing to
547 strictly control fetch time due to expensive and variable phone rates.
549 Combined with \-\-limitflush, it can be used to delete oversized
550 messages waiting on a server. In daemon mode, oversize notifications
551 are mailed to the calling user (see the \-\-warnings option). This
552 option does not work with ETRN or ODMR.
554 .B \-w <interval> | \-\-warnings <interval>
556 Takes an interval in seconds. When you call
558 with a 'limit' option in daemon mode, this controls the interval at
559 which warnings about oversized messages are mailed to the calling user
560 (or the user specified by the 'postmaster' option). One such
561 notification is always mailed at the end of the the first poll that
562 the oversized message is detected. Thereafter, re-notification is
563 suppressed until after the warning interval elapses (it will take
564 place at the end of the first following poll).
566 .B \-b <count> | \-\-batchlimit <count>
567 (Keyword: batchlimit)
568 Specify the maximum number of messages that will be shipped to an SMTP
569 listener before the connection is deliberately torn down and rebuilt
570 (defaults to 0, meaning no limit). An explicit \-\-batchlimit of 0
571 overrides any limits set in your run control file. While
572 \fBsendmail\fR(8) normally initiates delivery of a message immediately
573 after receiving the message terminator, some SMTP listeners are not so
574 prompt. MTAs like \fIsmail\fR(8) may wait till the
575 delivery socket is shut down to deliver. This may produce annoying
576 delays when \fIfetchmail\fR is processing very large batches. Setting
577 the batch limit to some nonzero size will prevent these delays. This
578 option does not work with ETRN or ODMR.
580 .B \-B <number> | \-\-fetchlimit <number>
581 (Keyword: fetchlimit)
582 Limit the number of messages accepted from a given server in a single
583 poll. By default there is no limit. An explicit \-\-fetchlimit of 0
584 overrides any limits set in your run control file.
585 This option does not work with ETRN or ODMR.
587 .B \-\-fetchsizelimit <number>
588 (Keyword: fetchsizelimit)
589 Limit the number of sizes of messages accepted from a given server in
590 a single transaction. This option is useful in reducing the delay in
591 downloading the first mail when there are too many mails in the
592 mailbox. By default, the limit is 100. If set to 0, sizes of all
593 messages are downloaded at the start.
594 This option does not work with ETRN or ODMR. For POP3, the only valid
597 .B \-\-fastuidl <number>
599 Do a binary instead of linear search for the first unseen UID. Binary
600 search avoids downloading the UIDs of all mails. This saves time
601 (especially in daemon mode) where downloading the same set of UIDs in
602 each poll is a waste of bandwidth. The number 'n' indicates how rarely
603 a linear search should be done. In daemon mode, linear search is used
604 once followed by binary searches in 'n-1' polls if 'n' is greater than
605 1; binary search is always used if 'n' is 1; linear search is always
606 used if 'n' is 0. In non-daemon mode, binary search is used if 'n' is
607 1; otherwise linear search is used.
608 This option works with POP3 only.
610 .B \-e <count> | \-\-expunge <count>
612 Arrange for deletions to be made final after a given number of
613 messages. Under POP2 or POP3, fetchmail cannot make deletions final
614 without sending QUIT and ending the session -- with this option on,
615 fetchmail will break a long mail retrieval session into multiple
616 sub-sessions, sending QUIT after each sub-session. This is a good
617 defense against line drops on POP3 servers that do not do the
618 equivalent of a QUIT on hangup. Under IMAP,
620 normally issues an EXPUNGE command after each deletion in order to
621 force the deletion to be done immediately. This is safest when your
622 connection to the server is flaky and expensive, as it avoids
623 resending duplicate mail after a line hit. However, on large
624 mailboxes the overhead of re-indexing after every message can slam the
625 server pretty hard, so if your connection is reliable it is good to do
626 expunges less frequently. Also note that some servers enforce a delay
627 of a few seconds after each quit, so fetchmail may not be able to get
628 back in immediately after an expunge -- you may see "lock busy" errors
629 if this happens. If you specify this option to an integer N,
632 to only issue expunges on every Nth delete. An argument of zero
633 suppresses expunges entirely (so no expunges at all will be done until
634 the end of run). This option does not work with ETRN or ODMR.
635 .SS Authentication Options
637 .B \-u <name> | \-\-user <name> | \-\-username <name>
638 (Keyword: user[name])
639 Specifies the user identification to be used when logging in to the mailserver.
640 The appropriate user identification is both server and user-dependent.
641 The default is your login name on the client machine that is running
643 See USER AUTHENTICATION below for a complete description.
645 .B \-I <specification> | \-\-interface <specification>
647 Require that a specific interface device be up and have a specific local
648 or remote IPv4 (IPv6 is not supported by this option yet) address (or
649 range) before polling. Frequently \fIfetchmail\fP
650 is used over a transient point-to-point TCP/IP link established directly
651 to a mailserver via SLIP or PPP. That is a relatively secure channel.
652 But when other TCP/IP routes to the mailserver exist (e.g. when the link
653 is connected to an alternate ISP), your username and password may be
654 vulnerable to snooping (especially when daemon mode automatically polls
655 for mail, shipping a clear password over the net at predictable
656 intervals). The \-\-interface option may be used to prevent this. When
657 the specified link is not up or is not connected to a matching IP
658 address, polling will be skipped. The format is:
661 interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]
664 The field before the first slash is the interface name (i.e. sl0, ppp0
665 etc.). The field before the second slash is the acceptable IP address.
666 The field after the second slash is a mask which specifies a range of
667 IP addresses to accept. If no mask is present 255.255.255.255 is
668 assumed (i.e. an exact match). This option is currently only supported
669 under Linux and FreeBSD. Please see the
671 section for below for FreeBSD specific information.
673 Note that this option may be removed from a future fetchmail version.
675 .B \-M <interface> | \-\-monitor <interface>
677 Daemon mode can cause transient links which are automatically taken down
678 after a period of inactivity (e.g. PPP links) to remain up
679 indefinitely. This option identifies a system TCP/IP interface to be
680 monitored for activity. After each poll interval, if the link is up but
681 no other activity has occurred on the link, then the poll will be
682 skipped. However, when fetchmail is woken up by a signal, the
683 monitor check is skipped and the poll goes through unconditionally.
684 This option is currently only supported under Linux and FreeBSD.
689 options to work for non root users under FreeBSD, the fetchmail binary
690 must be installed SGID kmem. This would be a security hole, but
691 fetchmail runs with the effective GID set to that of the kmem group
693 when interface data is being collected.
695 Note that this option may be removed from a future fetchmail version.
698 (Keyword: auth[enticate])
699 This option permits you to specify an authentication type (see USER
700 AUTHENTICATION below for details). The possible values are \fBany\fR,
701 \&\fBpassword\fR, \fBkerberos_v5\fR, \fBkerberos\fR (or, for
702 excruciating exactness, \fBkerberos_v4\fR), \fBgssapi\fR,
703 \fBcram\-md5\fR, \fBotp\fR, \fBntlm\fR, \fBmsn\fR (only for POP3) and
704 \fBssh\fR. When \fBany\fR (the default) is specified, fetchmail tries
705 first methods that don't require a password (GSSAPI, KERBEROS\ IV,
706 KERBEROS\ 5); then it looks for methods that mask your password
707 (CRAM-MD5, X\-OTP - note that NTLM and MSN are not autoprobed for POP3
708 and MSN is only supported for POP3); and only if the server doesn't
709 support any of those will it ship your password en clair. Other values
710 may be used to force various authentication methods
711 (\fBssh\fR suppresses authentication and is thus good for IMAP PREAUTH).
712 Any value other than \fBpassword\fR, \fBcram\-md5\fR, \fBntlm\fR,
713 \&\fBmsn\fR or \fBotp\fR suppresses fetchmail's normal inquiry for a
714 password. Specify \fBssh\fR when you are using an end-to-end secure
715 connection such as an ssh tunnel; specify \fBgssapi\fR or
716 \&\fBkerberos_v4\fR if you are using a protocol variant that employs
717 GSSAPI or K4. Choosing KPOP protocol automatically selects Kerberos
718 authentication. This option does not work with ETRN.
719 .SS Miscellaneous Options
721 .B \-f <pathname> | \-\-fetchmailrc <pathname>
722 Specify a non-default name for the
724 run control file. The pathname argument must be either "-" (a single
725 dash, meaning to read the configuration from standard input) or a
726 filename. Unless the \-\-version option is also on, a named file
727 argument must have permissions no more open than 0600 (u=rw,g=,o=) or
730 .B \-i <pathname> | \-\-idfile <pathname>
732 Specify an alternate name for the .fetchids file used to save POP3
735 .B \-n | \-\-norewrite
736 (Keyword: no rewrite)
739 edits RFC-822 address headers (To, From, Cc, Bcc, and Reply\-To) in
740 fetched mail so that any mail IDs local to the server are expanded to
741 full addresses (@ and the mailserver hostname are appended). This enables
742 replies on the client to get addressed correctly (otherwise your
743 mailer might think they should be addressed to local users on the
744 client machine!). This option disables the rewrite. (This option is
745 provided to pacify people who are paranoid about having an MTA edit
746 mail headers and want to know they can prevent it, but it is generally
747 not a good idea to actually turn off rewrite.)
748 When using ETRN or ODMR, the rewrite option is ineffective.
750 .B \-E <line> | \-\-envelope <line>
751 (Keyword: envelope; Multidrop only)
753 In the configuration file, an enhanced syntax is used:
755 .B envelope [<count>] <line>
757 This option changes the header
759 assumes will carry a copy of the mail's envelope address. Normally
760 this is 'X\-Envelope\-To', but as this header is not standard, practice
761 varies. See the discussion of multidrop address handling below. As a
762 special case, 'envelope "Received"' enables parsing of sendmail-style
763 Received lines. This is the default, and it should not be necessary
764 unless you have globally disabled Received parsing with 'no envelope'
765 in the \fI.fetchmailrc\fR file.
767 The optional count argument (only available in the configuration file)
768 determines how many header lines of this kind are skipped. A count of 1
769 means: skip the first, take the second. A count of 2 means: skip the
770 first and second, take the third, and so on.
772 .B \-Q <prefix> | \-\-qvirtual <prefix>
773 (Keyword: qvirtual; Multidrop only)
774 The string prefix assigned to this option will be removed from the user
775 name found in the header specified with the \fIenvelope\fR option
776 (\fIbefore\fR doing multidrop name mapping or localdomain checking,
777 if either is applicable). This option is useful if you are using
779 to collect the mail for an entire domain and your ISP (or your mail
780 redirection provider) is using qmail.
781 One of the basic features of qmail is the
785 message header. Whenever qmail delivers a message to a local mailbox
786 it puts the username and hostname of the envelope recipient on this
787 line. The major reason for this is to prevent mail loops. To set up
788 qmail to batch mail for a disconnected site the ISP-mailhost will have
789 normally put that site in its 'Virtualhosts' control file so it will
790 add a prefix to all mail addresses for this site. This results in mail
791 .\" The \&@\& tries to stop HTML converters from making a mailto URL here.
792 sent to 'username\&@\&userhost.userdom.dom.com' having a
793 \&'Delivered\-To:' line of the form:
795 Delivered\-To: mbox\-userstr\-username\&@\&userhost.example.com
797 The ISP can make the 'mbox\-userstr\-' prefix anything they choose
798 but a string matching the user host name is likely.
799 By using the option 'envelope Delivered\-To:' you can make fetchmail reliably
800 identify the original envelope recipient, but you have to strip the
801 'mbox\-userstr\-' prefix to deliver to the correct user.
802 This is what this option is for.
807 file, interpret any command-line options specified, and dump a
808 configuration report to standard output. The configuration report is
809 a data structure assignment in the language Python. This option
810 is meant to be used with an interactive
818 Removed before version 6.3.0, the required underlying inet6_apps library
819 had been discontinued and is no longer available.
821 .SH USER AUTHENTICATION AND ENCRYPTION
822 All modes except ETRN require authentication of the client to the server.
823 Normal user authentication in
825 is very much like the authentication mechanism of
827 The correct user-id and password depend upon the underlying security
828 system at the mailserver.
830 If the mailserver is a Unix machine on which you have an ordinary user
831 account, your regular login name and password are used with
833 If you use the same login name on both the server and the client machines,
834 you needn't worry about specifying a user-id with the
836 option -- the default behavior is to use your login name on the
837 client machine as the user-id on the server machine. If you use a
838 different login name on the server machine, specify that login name
841 option. e.g. if your login name is 'jsmith' on a machine named 'mailgrunt',
846 fetchmail \-u jsmith mailgrunt
848 The default behavior of
850 is to prompt you for your mailserver password before the connection is
851 established. This is the safest way to use
853 and ensures that your password will not be compromised. You may also specify
854 your password in your
856 file. This is convenient when using
858 in daemon mode or with scripts.
859 .SS Using netrc files
861 If you do not specify a password, and
863 cannot extract one from your
865 file, it will look for a
867 file in your home directory before requesting one interactively; if an
868 entry matching the mailserver is found in that file, the password will
869 be used. Fetchmail first looks for a match on poll name; if it finds none,
870 it checks for a match on via name. See the
872 man page for details of the syntax of the
874 file. To show a practical example, a .netrc might look like
878 machine hermes.example.org
883 You can repeat this block with different user information if you need to
884 provide more than one password.
886 This feature may allow you to avoid duplicating password
887 information in more than one file.
889 On mailservers that do not provide ordinary user accounts, your user-id and
890 password are usually assigned by the server administrator when you apply for
891 a mailbox on the server. Contact your server administrator if you don't know
892 the correct user-id and password for your mailbox account.
895 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
896 independent authentication using the
898 file on the mailserver side. Under this RPOP variant, a fixed
899 per-user ID equivalent to a password was sent in clear over a link to
900 a reserved port, with the command RPOP rather than PASS to alert the
901 server that it should do special checking. RPOP is supported
904 (you can specify 'protocol RPOP' to have the program send 'RPOP'
905 rather than 'PASS') but its use is strongly discouraged. This
906 facility was vulnerable to spoofing and was withdrawn in RFC1460.
908 RFC1460 introduced APOP authentication. In this variant of POP3,
909 you register an APOP password on your server host (the program
910 to do this with on the server is probably called \fIpopauth\fR(8)). You
911 put the same password in your
915 logs in, it sends a cryptographically secure hash of your password and
916 the server greeting time to the server, which can verify it by
917 checking its authorization database.
918 .SS Alternate authentication forms
920 If your \fIfetchmail\fR was built with Kerberos support and you specify
921 Kerberos authentication (either with \-\-auth or the \fI.fetchmailrc\fR
922 option \fBauthenticate kerberos_v4\fR) it will try to get a Kerberos
923 ticket from the mailserver at the start of each query. Note: if
924 either the pollname or via name is 'hesiod', fetchmail will try to use
925 Hesiod to look up the mailserver.
927 If you use POP3 or IMAP with GSSAPI authentication, \fIfetchmail\fR will
928 expect the server to have RFC1731- or RFC1734-conforming GSSAPI
929 capability, and will use it. Currently this has only been tested over
930 Kerberos V, so you're expected to already have a ticket-granting
931 ticket. You may pass a username different from your principal name
932 using the standard \fB\-\-user\fR command or by the \fI.fetchmailrc\fR
935 If your IMAP daemon returns the PREAUTH response in its greeting line,
936 fetchmail will notice this and skip the normal authentication step.
937 This can be useful, e.g. if you start imapd explicitly using ssh.
938 In this case you can declare the authentication value 'ssh' on that
939 site entry to stop \fI.fetchmail\fR from asking you for a password
942 If you are using POP3, and the server issues a one-time-password
943 challenge conforming to RFC1938, \fIfetchmail\fR will use your
944 password as a pass phrase to generate the required response. This
945 avoids sending secrets over the net unencrypted.
947 Compuserve's RPA authentication (similar to APOP) is supported. If you
948 compile in the support, \fIfetchmail\fR will try to perform an RPA pass-phrase
949 authentication instead of sending over the password en clair if it
950 detects "@compuserve.com" in the hostname.
952 If you are using IMAP, Microsoft's NTLM authentication (used by Microsoft
953 Exchange) is supported. If you compile in the support, \fIfetchmail\fR
954 will try to perform an NTLM authentication (instead of sending over the
955 password en clair) whenever the server returns AUTH=NTLM in its
956 capability response. Specify a user option value that looks like
957 \&'user@domain': the part to the left of the @ will be passed as the
958 username and the part to the right as the NTLM domain.
959 .SS Secure Socket Layers (SSL)
961 You can access SSL encrypted services by specifying the \-\-ssl option.
962 You can also do this using the "ssl" server option in the .fetchmailrc
963 file. With SSL encryption enabled, queries are initiated over a connection
964 after negotiating an SSL session. Some services, such as POP3 and IMAP,
965 have different well known ports defined for the SSL encrypted services.
966 The encrypted ports will be selected automatically when SSL is enabled and
967 no explicit port is specified.
969 When connecting to an SSL encrypted server, the server presents a certificate
970 to the client for validation. The certificate is checked to verify that
971 the common name in the certificate matches the name of the server being
972 contacted and that the effective and expiration dates in the certificate
973 indicate that it is currently valid. If any of these checks fail, a warning
974 message is printed, but the connection continues. The server certificate
975 does not need to be signed by any specific Certifying Authority and may
976 be a "self-signed" certificate.
978 Some SSL encrypted servers may request a client side certificate. A client
979 side public SSL certificate and private SSL key may be specified. If
980 requested by the server, the client certificate is sent to the server for
981 validation. Some servers may require a valid client certificate and may
982 refuse connections if a certificate is not provided or if the certificate
983 is not valid. Some servers may require client side certificates be signed
984 by a recognized Certifying Authority. The format for the key files and
985 the certificate files is that required by the underlying SSL libraries
986 (OpenSSL in the general case).
988 A word of care about the use of SSL: While above mentioned
989 setup with self-signed server certificates retrieved over the wires
990 can protect you from a passive eavesdropper it doesn't help against an
991 active attacker. It's clearly an improvement over sending the
992 passwords in clear but you should be aware that a man-in-the-middle
993 attack is trivially possible (in particular with tools such as dsniff,
994 http://www.monkey.org/~dugsong/dsniff/). Use of an ssh tunnel (see
995 below for some examples) is preferable if you care seriously about the
996 security of your mailbox.
1000 also supports authentication to the ESMTP server on the client side
1001 according to RFC 2554. You can specify a name/password pair to be
1002 used with the keywords 'esmtpname' and 'esmtppassword'; the former
1003 defaults to the username of the calling user.
1007 .B \-\-daemon <interval>
1012 in daemon mode. You must specify a numeric argument which is a
1013 polling interval in seconds.
1017 puts itself in background and runs forever, querying each specified
1018 host and then sleeping for the given polling interval.
1024 will, therefore, poll all the hosts described in your
1026 file (except those explicitly excluded with the 'skip' verb) once
1027 every fifteen minutes.
1029 It is possible to set a polling interval
1032 file by saying 'set daemon <interval>', where <interval> is an
1033 integer number of seconds. If you do this, fetchmail will always
1034 start in daemon mode unless you override it with the command-line
1035 option \-\-daemon 0 or \-d0.
1037 Only one daemon process is permitted per user; in daemon mode,
1039 makes a per-user lockfile to guarantee this.
1041 Normally, calling fetchmail with a daemon in the background sends a
1042 wake-up signal to the daemon, forcing it to poll mailservers
1043 immediately. (The wake-up signal is SIGHUP if fetchmail is running as
1044 root, SIGUSR1 otherwise.) The wake-up action also clears any 'wedged'
1045 flags indicating that connections have wedged due to failed
1046 authentication or multiple timeouts.
1050 will kill a running daemon process instead of waking it up (if there
1051 is no such process, \fIfetchmail\fP will notify you.
1052 If the \-\-quit option appears last on the command line, \fIfetchmail\fP
1053 will kill the running daemon process and then quit. Otherwise,
1054 \fIfetchmail\fP will first kill a running daemon process and then
1055 continue running with the other options.
1060 .B \-\-logfile <filename>
1061 option (keyword: set logfile) is only effective when fetchmail is
1062 detached. This option allows you to redirect status messages
1063 into a specified logfile (follow the option with the logfile name). The
1064 logfile is opened for append, so previous messages aren't deleted. This
1065 is primarily useful for debugging configurations.
1069 option (keyword: set syslog) allows you to redirect status and error
1070 messages emitted to the
1072 system daemon if available.
1073 Messages are logged with an id of \fBfetchmail\fR, the facility \fBLOG_MAIL\fR,
1074 and priorities \fBLOG_ERR\fR, \fBLOG_ALERT\fR or \fBLOG_INFO\fR.
1075 This option is intended for logging status and error messages which
1076 indicate the status of the daemon and the results while fetching mail
1078 Error messages for command line options and parsing the \fI.fetchmailrc\fR
1079 file are still written to stderr, or to the specified log file.
1082 option turns off use of
1084 assuming it's turned on in the
1089 .B \-\-logfile <file>
1096 option suppresses backgrounding and detachment of the
1097 daemon process from its control terminal. This is useful
1098 for debugging or when fetchmail runs as the child of a supervisor
1103 Note that this also causes the logfile option to be
1104 ignored (though perhaps it shouldn't).
1106 Note that while running in daemon mode polling a POP2 or IMAP2bis server,
1107 transient errors (such as DNS failures or sendmail delivery refusals)
1108 may force the fetchall option on for the duration of the next polling
1109 cycle. This is a robustness feature. It means that if a message is
1110 fetched (and thus marked seen by the mailserver) but not delivered
1111 locally due to some transient error, it will be re-fetched during the
1112 next poll cycle. (The IMAP logic doesn't delete messages until
1113 they're delivered, so this problem does not arise.)
1115 If you touch or change the
1117 file while fetchmail is running in daemon mode, this will be detected
1118 at the beginning of the next poll cycle. When a changed
1120 is detected, fetchmail rereads it and restarts from scratch (using
1121 exec(2); no state information is retained in the new instance). Note also
1122 that if you break the
1124 file's syntax, the new instance will softly and silently vanish away
1127 .SH ADMINISTRATIVE OPTIONS
1130 .B \-\-postmaster <name>
1131 option (keyword: set postmaster) specifies the last-resort username to
1132 which multidrop mail is to be forwarded if no matching local recipient
1133 can be found. It is also used as destination of undeliverable mail if
1134 the 'bouncemail' global option is off and additionally for spam-blocked
1135 mail if the 'bouncemail' global option is off and the 'spambounce'
1136 global option is on. This option defaults to the user who invoked
1138 If the invoking user is root, then the default of this option is
1139 the user 'postmaster'. Setting postmaster to the empty string causes
1140 such mail as described above to be discarded - this however is usually a
1142 See also the description of the 'FETCHMAILUSER' environment variable in
1143 the ENVIRONMENT section below.
1147 behaves like the "set no bouncemail" global option, which see.
1151 option (keyword: set invisible) tries to make fetchmail invisible.
1152 Normally, fetchmail behaves like any other MTA would -- it generates a
1153 Received header into each message describing its place in the chain of
1154 transmission, and tells the MTA it forwards to that the mail came from
1155 the machine fetchmail itself is running on. If the invisible option
1156 is on, the Received header is suppressed and fetchmail tries to spoof
1157 the MTA it forwards to into thinking it came directly from the
1162 option (keyword: set showdots) forces fetchmail to show progress dots
1163 even if the current tty is not stdout (for example logfiles).
1164 Starting with fetchmail version 5.3.0,
1165 progress dots are only shown on stdout by default.
1169 option, you can ask fetchmail to add information to the Received
1170 header on the form "polling {label} account {user}", where {label} is
1171 the account label (from the specified rcfile, normally ~/.fetchmailrc)
1172 and {user} is the username which is used to log on to the mail
1173 server. This header can be used to make filtering email where no
1174 useful header information is available and you want mail from
1175 different accounts sorted into different mailboxes (this could, for
1176 example, occur if you have an account on the same server running a
1177 mailing list, and are subscribed to the list using that account). The
1178 default is not adding any such header. In
1180 this is called 'tracepolls'.
1182 .SH RETRIEVAL FAILURE MODES
1183 The protocols \fIfetchmail\fR uses to talk to mailservers are next to
1184 bulletproof. In normal operation forwarding to port 25, no message is
1185 ever deleted (or even marked for deletion) on the host until the SMTP
1186 listener on the client side has acknowledged to \fIfetchmail\fR that
1187 the message has been either accepted for delivery or rejected due to a
1190 When forwarding to an MDA, however, there is more possibility
1191 of error. Some MDAs are 'safe' and reliably return a nonzero status
1192 on any delivery error, even one due to temporary resource limits.
1195 program is like this; so are most programs designed as mail transport
1198 including the sendmail wrapper of Postfix and
1200 These programs give back a reliable positive acknowledgement and
1201 can be used with the mda option with no risk of mail loss. Unsafe
1202 MDAs, though, may return 0 even on delivery failure. If this
1203 happens, you will lose mail.
1205 The normal mode of \fIfetchmail\fR is to try to download only 'new'
1206 messages, leaving untouched (and undeleted) messages you have already
1207 read directly on the server (or fetched with a previous \fIfetchmail
1208 --keep\fR). But you may find that messages you've already read on the
1209 server are being fetched (and deleted) even when you don't specify
1210 --all. There are several reasons this can happen.
1212 One could be that you're using POP2. The POP2 protocol includes no
1213 representation of 'new' or 'old' state in messages, so \fIfetchmail\fR
1214 must treat all messages as new all the time. But POP2 is obsolete, so
1217 A potential POP3 problem might be servers that insert messages
1218 in the middle of mailboxes (some VMS implementations of mail are
1219 rumored to do this). The \fIfetchmail\fR code assumes that new
1220 messages are appended to the end of the mailbox; when this is not true
1221 it may treat some old messages as new and vice versa. Using UIDL might
1222 fix this, otherwise, consider switching to IMAP.
1224 Yet another POP3 problem is that if they can't make tempfiles in the
1225 user's home directory, some POP3 servers will hand back an
1226 undocumented response that causes fetchmail to spuriously report "No
1229 The IMAP code uses the presence or absence of the server flag \eSeen
1230 to decide whether or not a message is new. This isn't the right thing
1231 to do, fetchmail should check the UIDVALIDITY and use UID, but it
1232 doesn't do that yet. Under Unix, it counts on your IMAP server to notice
1233 the BSD-style Status flags set by mail user agents and set the \eSeen
1234 flag from them when appropriate. All Unix IMAP servers we know of do
1235 this, though it's not specified by the IMAP RFCs. If you ever trip over
1236 a server that doesn't, the symptom will be that messages you have
1237 already read on your host will look new to the server. In this
1238 (unlikely) case, only messages you fetched with \fIfetchmail \-\-keep\fR
1239 will be both undeleted and marked old.
1241 In ETRN and ODMR modes, \fIfetchmail\fR does not actually retrieve messages;
1242 instead, it asks the server's SMTP listener to start a queue flush
1243 to the client via SMTP. Therefore it sends only undelivered messages.
1246 Many SMTP listeners allow administrators to set up 'spam filters' that
1247 block unsolicited email from specified domains. A MAIL FROM or DATA line that
1248 triggers this feature will elicit an SMTP response which
1249 (unfortunately) varies according to the listener.
1253 return an error code of 571.
1255 According to RFC2821, the correct thing to return in this situation is
1256 550 "Requested action not taken: mailbox unavailable" (the draft adds
1257 "[E.g., mailbox not found, no access, or command rejected for policy
1260 Older versions of the
1262 MTA return 501 "Syntax error in parameters or arguments".
1266 MTA runs 554 as an antispam response.
1269 may reject code with a 500 response (followed by an enhanced status
1270 code that contains more information).
1274 treats as antispam responses and discards
1275 the message can be set with the 'antispam' option. This is one of the
1277 three circumstance under which fetchmail ever discards mail (the others
1278 are the 552 and 553 errors described below, and the suppression of
1279 multidropped messages with a message-ID already seen).
1283 is fetching from an IMAP server, the antispam response will be detected and
1284 the message rejected immediately after the headers have been fetched,
1285 without reading the message body. Thus, you won't pay for downloading
1286 spam message bodies.
1288 By default, the list of antispam responses is empty.
1290 If the \fIspambounce\fR global option is on, mail that is spam-blocked
1291 triggers an RFC1892/RFC1894 bounce message informing the originator that
1292 we do not accept mail from it. See also BUGS.
1294 .SH SMTP/ESMTP ERROR HANDLING
1295 Besides the spam-blocking described above, fetchmail takes special
1296 actions on the following SMTP/ESMTP error responses
1298 452 (insufficient system storage)
1299 Leave the message in the server mailbox for later retrieval.
1301 552 (message exceeds fixed maximum message size)
1302 Delete the message from the server. Send bounce-mail to the
1305 553 (invalid sending domain)
1306 Delete the message from the server. Don't even try to send
1307 bounce-mail to the originator.
1309 Other errors trigger bounce mail back to the originator. See also BUGS.
1311 .SH THE RUN CONTROL FILE
1312 The preferred way to set up fetchmail is to write a
1313 \&\fI.fetchmailrc\fR file in your home directory (you may do this
1314 directly, with a text editor, or indirectly via \fIfetchmailconf\fR).
1315 When there is a conflict between the command-line arguments and the
1316 arguments in this file, the command-line arguments take precedence.
1318 To protect the security of your passwords,
1319 your \fI~/.fetchmailrc\fR may not normally have more than 0600 (u=rw,g=,o=) permissions;
1321 will complain and exit otherwise (this check is suppressed when
1324 You may read the \fI.fetchmailrc\fR file as a list of commands to
1327 is called with no arguments.
1328 .SS Run Control Syntax
1330 Comments begin with a '#' and extend through the end of the line.
1331 Otherwise the file consists of a series of server entries or global
1332 option statements in a free-format, token-oriented syntax.
1334 There are four kinds of tokens: grammar keywords, numbers
1335 (i.e. decimal digit sequences), unquoted strings, and quoted strings.
1336 A quoted string is bounded by double quotes and may contain
1337 whitespace (and quoted digits are treated as a string). Note that
1338 quoted strings will also contain line feed characters if they run across
1339 two or more lines, unless you use a backslash to join lines (see below).
1340 An unquoted string is any whitespace-delimited token that is neither
1341 numeric, string quoted nor contains the special characters ',', ';',
1344 Any amount of whitespace separates tokens in server entries, but is
1345 otherwise ignored. You may use backslash escape sequences (\en for LF,
1346 \&\et for HT, \&\eb for BS, \er for CR, \e\fInnn\fP for decimal (where
1347 nnn cannot start with a 0), \e0\fIooo\fP for octal, and \ex\fIhh\fP for
1348 hex) to embed non-printable characters or string delimiters in strings.
1349 In quoted strings, a backslash at the very end of a line will cause the
1350 backslash itself and the line feed (LF or NL, new line) character to be
1351 ignored, so that you can wrap long strings. Without the backslash at the
1352 line end, the line feed character would become part of the string.
1355 while these resemble C-style escape sequences, they are not the same.
1356 fetchmail only supports these eight styles. C supports more escape
1357 sequences that consist of backslash (\e) and a single character, but
1358 does not support decimal codes and does not require the leading 0 in
1359 octal notation. Example: fetchmail interprets \e233 the same as \exE9
1360 (Latin small letter e with acute), where C would interpret \e233 as
1361 octal 0233 = \ex9B (CSI, control sequence introducer).
1363 Each server entry consists of one of the keywords 'poll' or 'skip',
1364 followed by a server name, followed by server options, followed by any
1365 number of user descriptions. Note: the most common cause of syntax
1366 errors is mixing up user and server options.
1368 For backward compatibility, the word 'server' is a synonym for 'poll'.
1370 You can use the noise keywords 'and', 'with',
1371 \&'has', 'wants', and 'options' anywhere in an entry to make
1372 it resemble English. They're ignored, but but can make entries much
1373 easier to read at a glance. The punctuation characters ':', ';' and
1374 \&',' are also ignored.
1377 The 'poll' verb tells fetchmail to query this host when it is run with
1378 no arguments. The 'skip' verb tells
1380 not to poll this host unless it is explicitly named on the command
1381 line. (The 'skip' verb allows you to experiment with test entries
1382 safely, or easily disable entries for hosts that are temporarily down.)
1384 .SS Keyword/Option Summary
1385 Here are the legal options. Keyword suffixes enclosed in
1386 square brackets are optional. Those corresponding to short command-line
1387 options are followed by '\-' and the appropriate option letter. If
1388 option is only relevant to a single mode of operation, it is noted as
1389 's' or 'm' for singledrop- or multidrop-mode, respectively.
1391 Here are the legal global options:
1395 Keyword Opt Mode Function
1397 set daemon \-d \& T{
1398 Set a background poll interval in seconds.
1400 set postmaster \& \& T{
1401 Give the name of the last-resort mail recipient (default: user running
1402 fetchmail, "postmaster" if run by the root user)
1404 set bouncemail \& \& T{
1405 Direct error mail to the sender (default)
1407 set no bouncemail \& \& T{
1408 Direct error mail to the local postmaster (as per the 'postmaster'
1409 global option above).
1411 set no spambounce \& \& T{
1412 Do not bounce spam-blocked mail (default).
1414 set spambounce \& \& T{
1415 Bounce blocked spam-blocked mail (as per the 'antispam' user option)
1416 back to the destination as indicated by the 'bouncemail' global option.
1417 Warning: Do not use this to bounce spam back to the sender - most spam
1418 is sent with false sender address and thus this option hurts innocent
1421 set logfile \-L \& T{
1422 Name of a file to append error and status messages to.
1424 set idfile \-i \& T{
1425 Name of the file to store UID lists in.
1428 Do error logging through syslog(3).
1430 set no syslog \& \& T{
1431 Turn off error logging through syslog(3). (default)
1433 set properties \& \& T{
1434 String value that is ignored by fetchmail (may be used by extension
1439 Here are the legal server options:
1443 Keyword Opt Mode Function
1446 Specify DNS name of mailserver, overriding poll name
1448 proto[col] \-p \& T{
1449 Specify protocol (case insensitive):
1450 POP2, POP3, IMAP, APOP, KPOP
1452 local[domains] \& m T{
1453 Specify domain(s) to be regarded as local
1456 Specify TCP/IP service port (obsolete, use 'service' instead).
1459 Specify service name (a numeric value is also allowed and
1460 considered a TCP/IP port number).
1462 auth[enticate] \& \& T{
1463 Set authentication type (default 'any')
1466 Server inactivity timeout in seconds (default 300)
1469 Specify envelope-address header name
1472 Disable looking for envelope address
1475 Qmail virtual domain prefix to remove from user name
1478 Specify alternate DNS names of mailserver
1481 specify IP interface(s) that must be up for server poll to take place
1484 Specify IP address to monitor for activity
1487 Specify command through which to make server connections.
1490 Specify command through which to make listener connections.
1493 Enable DNS lookup for multidrop (default)
1496 Disable DNS lookup for multidrop
1499 Do comparison by IP address for multidrop
1501 no checkalias \& m T{
1502 Do comparison by name for multidrop (default)
1505 Force POP3 to use client-side UIDLs (recommended)
1508 Turn off POP3 use of client-side UIDLs (default)
1511 Only check this site every N poll cycles; N is a numeric argument.
1514 Add poll tracing information to the Received header
1517 Set Kerberos principal (only useful with imap and kerberos)
1520 Set name for RFC2554 authentication to the ESMTP server.
1522 esmtppassword \& \& T{
1523 Set password for RFC2554 authentication to the ESMTP server.
1527 Here are the legal user options:
1531 Keyword Opt Mode Function
1533 user[name] \-u \& T{
1534 Set remote user name
1535 (local user name if name followed by 'here')
1538 Connect local and remote user names
1541 Connect local and remote user names
1544 Specify remote account password
1547 Connect to server over the specified base protocol using SSL encryption
1550 Specify file for client side public SSL certificate
1553 Specify file for client side private SSL key
1556 Force ssl protocol for connection
1559 Specify remote folder to query
1562 Specify smtp host(s) to forward to
1564 fetchdomains \& m T{
1565 Specify domains for which mail should be fetched
1567 smtpaddress \-D \& T{
1568 Specify the domain to be put in RCPT TO lines
1571 Specify the user and domain to be put in RCPT TO lines
1574 Specify what SMTP returns are interpreted as spam-policy blocks
1577 Specify MDA for local delivery
1580 Specify BSMTP batch file to append to
1583 Command to be executed before each connection
1585 postconnect \& \& T{
1586 Command to be executed after each connection
1589 Don't delete seen messages from server
1592 Flush all seen messages before querying (DANGEROUS)
1595 Flush all oversized messages before querying
1598 Fetch all messages whether seen or not
1601 Rewrite destination addresses for reply (default)
1604 Strip carriage returns from ends of lines
1607 Force carriage returns at ends of lines
1610 Force BODY=8BITMIME to ESMTP listener
1613 Strip Status and X-Mozilla-Status lines out of incoming mail
1615 dropdelivered \& \& T{
1616 Strip Delivered-To lines out of incoming mail
1619 Convert quoted-printable to 8-bit in MIME messages
1622 Idle waiting for new messages after each poll (IMAP only)
1625 Delete seen messages from server (default)
1628 Don't flush all seen messages before querying (default)
1630 no fetchall \& \& T{
1631 Retrieve only new messages (default)
1634 Don't rewrite headers
1637 Don't strip carriage returns (default)
1640 Don't force carriage returns at EOL (default)
1642 no pass8bits \& \& T{
1643 Don't force BODY=8BITMIME to ESMTP listener (default)
1645 no dropstatus \& \& T{
1646 Don't drop Status headers (default)
1648 no dropdelivered \& \& T{
1649 Don't drop Delivered\-To headers (default)
1651 no mimedecode \& \& T{
1652 Don't convert quoted-printable to 8-bit in MIME messages (default)
1655 Don't idle waiting for new messages after each poll (IMAP only)
1658 Set message size limit
1661 Set message size warning interval
1663 batchlimit \-b \& T{
1664 Max # messages to forward in single connect
1666 fetchlimit \-B \& T{
1667 Max # messages to fetch in single connect
1669 fetchsizelimit \& \& T{
1670 Max # message sizes to fetch in single transaction
1673 Use binary search for first unseen message (POP3 only)
1676 Perform an expunge on every #th message (IMAP and POP3 only)
1679 String value is ignored by fetchmail (may be used by extension scripts)
1683 Remember that all user options must \fIfollow\fR all server options.
1685 In the .fetchmailrc file, the 'envelope' string argument may be
1686 preceded by a whitespace-separated number. This number, if specified,
1687 is the number of such headers to skip over (that is, an argument of 1
1688 selects the second header of the given type). This is sometime useful
1689 for ignoring bogus envelope headers created by an ISP's local delivery
1690 agent or internal forwards (through mail inspection systems, for
1692 .SS Keywords Not Corresponding To Option Switches
1694 The 'folder' and 'smtphost' options (unlike their command-line
1695 equivalents) can take a space- or comma-separated list of names
1698 All options correspond to the obvious command-line arguments, except
1699 the following: 'via', 'interval', 'aka', 'is', 'to', 'dns'/'no dns',
1700 \&'checkalias'/'no checkalias', 'password', 'preconnect', 'postconnect',
1701 \&'localdomains', 'stripcr'/'no stripcr', 'forcecr'/'no forcecr',
1702 \&'pass8bits'/'no pass8bits' 'dropstatus/no dropstatus',
1703 \&'dropdelivered/no dropdelivered', 'mimedecode/no mimedecode', 'idle/no
1704 idle', and 'no envelope'.
1706 The 'via' option is for if you want to have more
1707 than one configuration pointing at the same site. If it is present,
1708 the string argument will be taken as the actual DNS name of the
1709 mailserver host to query.
1710 This will override the argument of poll, which can then simply be a
1711 distinct label for the configuration (e.g. what you would give on the
1712 command line to explicitly query this host).
1714 The 'interval' option (which takes a numeric argument) allows you to poll a
1715 server less frequently than the basic poll interval. If you say
1716 \&'interval N' the server this option is attached to will only be
1717 queried every N poll intervals.
1719 The 'is' or 'to' keywords associate the following local (client)
1720 name(s) (or server-name to client-name mappings separated by =) with
1721 the mailserver user name in the entry. If an is/to list has '*' as
1722 its last name, unrecognized names are simply passed through.
1724 A single local name can be used to support redirecting your mail when
1725 your username on the client machine is different from your name on the
1726 mailserver. When there is only a single local name, mail is forwarded
1727 to that local username regardless of the message's Received, To, Cc,
1728 and Bcc headers. In this case
1730 never does DNS lookups.
1732 When there is more than one local name (or name mapping) the
1733 \fIfetchmail\fR code does look at the Received, To, Cc, and Bcc
1734 headers of retrieved mail (this is 'multidrop mode'). It looks for
1735 addresses with hostname parts that match your poll name or your 'via',
1736 \&'aka' or 'localdomains' options, and usually also for hostname parts
1737 which DNS tells it are aliases of the mailserver. See the discussion
1738 of 'dns', 'checkalias', 'localdomains', and 'aka' for details on how
1739 matching addresses are handled.
1741 If \fIfetchmail\fR cannot match any mailserver usernames or
1742 localdomain addresses, the mail will be bounced.
1743 Normally it will be bounced to the sender, but if the 'bouncemail'
1744 global option is off, the mail will go to the local postmaster instead.
1745 (see the 'postmaster' global option). See also BUGS.
1747 The 'dns' option (normally on) controls the way addresses from
1748 multidrop mailboxes are checked. On, it enables logic to check each
1749 host address that does not match an 'aka' or 'localdomains' declaration
1750 by looking it up with DNS. When a mailserver username is recognized
1751 attached to a matching hostname part, its local mapping is added to
1752 the list of local recipients.
1754 The 'checkalias' option (normally off) extends the lookups performed
1755 by the 'dns' keyword in multidrop mode, providing a way to cope with
1756 remote MTAs that identify themselves using their canonical name, while
1757 they're polled using an alias.
1758 When such a server is polled, checks to extract the envelope address
1761 reverts to delivery using the To/Cc/Bcc headers (See below
1762 \&'Header vs. Envelope addresses').
1763 Specifying this option instructs
1765 to retrieve all the IP addresses associated with both the poll name
1766 and the name used by the remote MTA and to do a comparison of the IP
1767 addresses. This comes in handy in situations where the remote server
1768 undergoes frequent canonical name changes, that would otherwise
1769 require modifications to the rcfile. 'checkalias' has no effect if
1770 \&'no dns' is specified in the rcfile.
1772 The 'aka' option is for use with multidrop mailboxes. It allows you
1773 to pre-declare a list of DNS aliases for a server. This is an
1774 optimization hack that allows you to trade space for speed. When
1776 while processing a multidrop mailbox, grovels through message headers
1777 looking for names of the mailserver, pre-declaring common ones can
1778 save it from having to do DNS lookups. Note: the names you give
1779 as arguments to 'aka' are matched as suffixes -- if you specify
1780 (say) 'aka netaxs.com', this will match not just a hostname
1781 netaxs.com, but any hostname that ends with '.netaxs.com'; such as
1782 (say) pop3.netaxs.com and mail.netaxs.com.
1784 The 'localdomains' option allows you to declare a list of domains
1785 which fetchmail should consider local. When fetchmail is parsing
1786 address lines in multidrop modes, and a trailing segment of a host
1787 name matches a declared local domain, that address is passed through
1788 to the listener or MDA unaltered (local-name mappings are \fInot\fR
1791 If you are using 'localdomains', you may also need to specify \&'no
1792 envelope', which disables \fIfetchmail\fR's normal attempt to deduce
1793 an envelope address from the Received line or X-Envelope-To header or
1794 whatever header has been previously set by 'envelope'. If you set 'no
1795 envelope' in the defaults entry it is possible to undo that in
1796 individual entries by using 'envelope <string>'. As a special case,
1797 \&'envelope "Received"' restores the default parsing of
1800 The \fBpassword\fR option requires a string argument, which is the password
1801 to be used with the entry's server.
1803 The 'preconnect' keyword allows you to specify a shell command to be
1804 executed just before each time
1806 establishes a mailserver connection. This may be useful if you are
1807 attempting to set up secure POP connections with the aid of
1809 If the command returns a nonzero status, the poll of that mailserver
1812 Similarly, the 'postconnect' keyword similarly allows you to specify a
1813 shell command to be executed just after each time a mailserver
1814 connection is taken down.
1816 The 'forcecr' option controls whether lines terminated by LF only are
1817 given CRLF termination before forwarding. Strictly speaking RFC821
1818 requires this, but few MTAs enforce the requirement it so this option
1819 is normally off (only one such MTA, qmail, is in significant use at
1822 The 'stripcr' option controls whether carriage returns are stripped
1823 out of retrieved mail before it is forwarded. It is normally not
1824 necessary to set this, because it defaults to 'on' (CR stripping
1825 enabled) when there is an MDA declared but 'off' (CR stripping
1826 disabled) when forwarding is via SMTP. If 'stripcr' and 'forcecr' are
1827 both on, 'stripcr' will override.
1829 The 'pass8bits' option exists to cope with Microsoft mail programs that
1830 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
1831 this option off (the default) and such a header present,
1833 declares BODY=7BIT to an ESMTP-capable listener; this causes problems for
1834 messages actually using 8-bit ISO or KOI-8 character sets, which will
1835 be garbled by having the high bits of all characters stripped. If
1836 \&'pass8bits' is on,
1838 is forced to declare BODY=8BITMIME to any ESMTP-capable listener. If
1839 the listener is 8-bit-clean (as all the major ones now are) the right
1840 thing will probably result.
1842 The 'dropstatus' option controls whether nonempty Status and
1843 X-Mozilla-Status lines are retained in fetched mail (the default) or
1844 discarded. Retaining them allows your MUA to see what messages (if
1845 any) were marked seen on the server. On the other hand, it can
1846 confuse some new-mail notifiers, which assume that anything with a
1847 Status line in it has been seen. (Note: the empty Status lines
1848 inserted by some buggy POP servers are unconditionally discarded.)
1850 The 'dropdelivered' option controls whether Delivered\-To headers will
1851 be kept in fetched mail (the default) or discarded. These headers are
1852 added by Qmail and Postfix mailservers in order to avoid mail loops but
1853 may get in your way if you try to "mirror" a mailserver within the same
1854 domain. Use with caution.
1856 The 'mimedecode' option controls whether MIME messages using the
1857 quoted-printable encoding are automatically converted into pure 8-bit
1858 data. If you are delivering mail to an ESMTP-capable, 8-bit-clean
1859 listener (that includes all of the major MTAs like sendmail), then
1860 this will automatically convert quoted-printable message headers and
1861 data into 8-bit data, making it easier to understand when reading
1862 mail. If your e-mail programs know how to deal with MIME messages,
1863 then this option is not needed. The mimedecode option is off by
1864 default, because doing RFC2047 conversion on headers throws away
1865 character-set information and can lead to bad results if the encoding
1866 of the headers differs from the body encoding.
1868 The 'idle' option is intended to be used with IMAP servers supporting
1869 the RFC2177 IDLE command extension, but does not strictly require it.
1870 If it is enabled, and fetchmail detects that IDLE is supported, an
1871 IDLE will be issued at the end of each poll. This will tell the IMAP
1872 server to hold the connection open and notify the client when new mail
1873 is available. If IDLE is not supported, fetchmail will simulate it by
1874 periodically issuing NOOP. If you need to poll a link frequently, IDLE
1875 can save bandwidth by eliminating TCP/IP connects and LOGIN/LOGOUT
1876 sequences. On the other hand, an IDLE connection will eat almost all
1877 of your fetchmail's time, because it will never drop the connection
1878 and allow other pools to occur unless the server times out the IDLE.
1879 It also doesn't work with multiple folders; only the first folder will
1883 The 'properties' option is an extension mechanism. It takes a string
1884 argument, which is ignored by fetchmail itself. The string argument may be
1885 used to store configuration information for scripts which require it.
1886 In particular, the output of '\-\-configdump' option will make properties
1887 associated with a user entry readily available to a Python script.
1889 .SS Miscellaneous Run Control Options
1890 The words 'here' and 'there' have useful English-like
1891 significance. Normally 'user eric is esr' would mean that
1892 mail for the remote user 'eric' is to be delivered to 'esr',
1893 but you can make this clearer by saying 'user eric there is esr here',
1894 or reverse it by saying 'user esr here is eric there'
1896 Legal protocol identifiers for use with the 'protocol' keyword are:
1900 pop2 (or POP2) (legacy, to be removed from future release)
1909 Legal authentication types are 'any', 'password', 'kerberos',
1910 \&'kerberos_v4', 'kerberos_v5' and 'gssapi', 'cram\-md5', 'otp', 'msn'
1911 (only for POP3), 'ntlm', 'ssh'. The 'password' type specifies
1912 authentication by normal transmission of a password (the password may be
1913 plain text or subject to protocol-specific encryption as in APOP);
1914 \&'kerberos' tells \fIfetchmail\fR to try to get a Kerberos ticket at the
1915 start of each query instead, and send an arbitrary string as the
1916 password; and 'gssapi' tells fetchmail to use GSSAPI authentication.
1917 See the description of the 'auth' keyword for more.
1919 Specifying 'kpop' sets POP3 protocol over port 1109 with Kerberos V4
1920 authentication. These defaults may be overridden by later options.
1922 There are some global option statements: 'set logfile'
1923 followed by a string sets the same global specified by \-\-logfile. A
1924 command-line \-\-logfile option will override this. Note that \-\-logfile is
1925 only effective if fetchmail detaches itself from the terminal. Also,
1926 'set daemon' sets the poll interval as \-\-daemon does. This can be
1927 overridden by a command-line \-\-daemon option; in particular \-\-daemon\~0
1928 can be used to force foreground operation. The 'set postmaster'
1929 statement sets the address to which multidrop mail defaults if there are
1930 no local matches. Finally, 'set syslog' sends log messages to
1933 .SH DEBUGGING FETCHMAIL
1934 .SS Fetchmail crashing
1935 There are various ways in that fetchmail may "crash", i. e. stop
1936 operation suddenly and unexpectedly. A "crash" usually refers to an
1937 error condition that the software did not handle by itself. A well-known
1938 failure mode is the "segmentation fault" or "signal 11" or "SIGSEGV" or
1939 just "segfault" for short. These can be caused by hardware or by software
1940 problems. Software-induced segfaults can usually be reproduced easily
1941 and in the same place, whereas hardware-induced segfaults can go away if
1942 the computer is rebooted, or powered off for a few hours, and can happen
1943 in random locations even if you use the software the same way.
1945 For solving hardware-induced segfaults, find the faulty component and repair or
1946 replace it. <http://www.bitwizard.nl/sig11/> may help you with details.
1948 For solving software-induced segfaults, the developers may need a "stack
1951 .SS Enabling fetchmail core dumps
1952 By default, fetchmail suppresses core dumps as these might contain
1953 passwords and other sensitive information. For debugging fetchmail
1954 crashes, obtaining a "stack backtrace" from a core dump is often the
1955 quickest way to solve the problem, and when posting your problem on a
1956 mailing list, the developers may ask you for a "backtrace".
1958 1. To get useful backtraces, fetchmail needs to be installed without
1959 getting stripped of its compilation symbols. Unfortunately, most
1960 binary packages that are installed are stripped, and core files from
1961 symbol-stripped programs are worthless. So you may need to recompile
1962 fetchmail. On many systems, you can type
1965 file `which fetchmail`
1968 to find out if fetchmail was symbol-stripped or not. If yours was
1969 unstripped, fine, proceed, if it was stripped, you need to recompile the
1970 source code first. You do not usually need to install fetchmail in order
1973 2. The shell environment that starts fetchmail needs to enable core
1974 dumps. The key is the "maximum core (file) size" that can usually be
1975 configured with a tool named "limit" or "ulimit". See the documentation
1976 for your shell for details. In the popular bash shell, "ulimit \-Sc
1977 unlimited" will allow the core dump.
1979 3. You need to tell fetchmail, too, to allow core dumps. To do
1980 this, run fetchmail with the \fB\-d0 \-v\fP options. It is often easier
1981 to also add \fB\-\-nosyslog \-N\fR as well.
1983 Finally, you need to reproduce the crash. You can just start fetchmail
1984 from the directory where you compiled it by typing \fB./fetchmail\fR,
1985 so the complete command line will start with \fB./fetchmail \-Nvd0
1986 \&\-\-nosyslog\fR and perhaps list your other options.
1988 After the crash, run your debugger to obtain the core dump. The
1989 debugger will often be GNU GDB, you can then type (adjust paths as
1990 necessary) \fBgdb ./fetchmail fetchmail.core\fR and then, after GDB
1991 has started up and read all its files, type \fBbacktrace full\fR, save
1992 the output (copy & paste will do, the backtrace will be read by a human)
1993 and then type \fBquit\fR to leave gdb.
1995 on some systems, the core
1996 files have different names, they might contain a number instead of the
1997 program name, or number and name, but it will usually have "core" as
2000 .SH INTERACTION WITH RFC 822
2001 When trying to determine the originating address of a message,
2002 fetchmail looks through headers in the following order:
2006 Resent-Sender: (ignored if it doesn't contain an @ or !)
2007 Sender: (ignored if it doesn't contain an @ or !)
2014 The originating address is used for logging, and to set the MAIL FROM
2015 address when forwarding to SMTP. This order is intended to cope
2016 gracefully with receiving mailing list messages in multidrop mode. The
2017 intent is that if a local address doesn't exist, the bounce message
2018 won't be returned blindly to the author or to the list itself, but
2019 rather to the list manager (which is less annoying).
2021 In multidrop mode, destination headers are processed as follows:
2022 First, fetchmail looks for the Received: header (or whichever one is
2023 specified by the 'envelope' option) to determine the local
2024 recipient address. If the mail is addressed to more than one recipient,
2025 the Received line won't contain any information regarding recipient addresses.
2027 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
2028 lines. If they exist, they should contain the final recipients and
2029 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent\-*
2030 lines don't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
2031 looked for. (The presence of a Resent\-To: is taken to imply that the
2032 person referred by the To: address has already received the original
2035 .SH CONFIGURATION EXAMPLES
2036 Note that although there are password declarations in a good many
2037 of the examples below, this is mainly for illustrative purposes.
2038 We recommend stashing account/password pairs in your $HOME/.netrc
2039 file, where they can be used not just by fetchmail but by ftp(1) and
2045 poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD
2051 poll pop.provider.net protocol pop3 username "jsmith" password "secret1"
2054 Or, using some abbreviations:
2057 poll pop.provider.net proto pop3 user "jsmith" password "secret1"
2060 Multiple servers may be listed:
2063 poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
2064 poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"
2067 Here's a version of those two with more whitespace and some noise words:
2070 poll pop.provider.net proto pop3
2071 user "jsmith", with password secret1, is "jsmith" here;
2072 poll other.provider.net proto pop2:
2073 user "John.Smith", with password "My^Hat", is "John.Smith" here;
2076 This version is much easier to read and doesn't cost significantly
2077 more (parsing is done only once, at startup time).
2080 If you need to include whitespace in a parameter string, enclose the
2081 string in double quotes. Thus:
2084 poll mail.provider.net with proto pop3:
2085 user "jsmith" there has password "u can't krak this"
2086 is jws here and wants mda "/bin/mail"
2089 You may have an initial server description headed by the keyword
2090 \&'defaults' instead of 'poll' followed by a name. Such a record
2091 is interpreted as defaults for all queries to use. It may be overwritten
2092 by individual server descriptions. So, you could write:
2097 poll pop.provider.net
2099 poll mail.provider.net
2100 user "jjsmith" there has password "secret2"
2103 It's possible to specify more than one user per server (this is only
2104 likely to be useful when running fetchmail in daemon mode as root).
2105 The 'user' keyword leads off a user description, and every user specification
2106 in a multi-user entry must include it. Here's an example:
2109 poll pop.provider.net proto pop3 port 3111
2110 user "jsmith" with pass "secret1" is "smith" here
2111 user jones with pass "secret2" is "jjones" here keep
2114 This associates the local username 'smith' with the pop.provider.net
2115 username 'jsmith' and the local username 'jjones' with the
2116 pop.provider.net username 'jones'. Mail for 'jones' is kept on the
2117 server after download.
2119 Here's what a simple retrieval configuration for a multi-drop mailbox
2123 poll pop.provider.net:
2124 user maildrop with pass secret1 to golux 'hurkle'='happy' snark here
2127 This says that the mailbox of account 'maildrop' on the server is a
2128 multi-drop box, and that messages in it should be parsed for the
2129 server user names 'golux', 'hurkle', and 'snark'. It further
2130 specifies that 'golux' and 'snark' have the same name on the
2131 client as on the server, but mail for server user 'hurkle' should be
2132 delivered to client user 'happy'.
2134 Here's an example of another kind of multidrop connection:
2137 poll pop.provider.net localdomains loonytoons.org toons.org:
2138 user maildrop with pass secret1 to * here
2141 This also says that the mailbox of account 'maildrop' on the server is
2142 a multi-drop box. It tells fetchmail that any address in the
2143 loonytoons.org or toons.org domains (including sub-domain addresses like
2144 \&'joe@daffy.loonytoons.org') should be passed through to the local SMTP
2145 listener without modification. Be careful of mail loops if you do this!
2147 Here's an example configuration using ssh and the plugin option. The
2148 queries are made directly on the stdin and stdout of imapd via ssh.
2149 Note that in this setup, IMAP authentication can be skipped.
2152 poll mailhost.net with proto imap:
2153 plugin "ssh %h /usr/sbin/imapd" auth ssh;
2154 user esr is esr here
2157 .SH THE USE AND ABUSE OF MULTIDROP MAILBOXES
2158 Use the multiple-local-recipients feature with caution -- it can bite.
2159 All multidrop features are ineffective in ETRN and ODMR modes.
2161 Also, note that in multidrop mode duplicate mails are suppressed. A
2162 piece of mail is considered duplicate if it has the same message-ID as
2163 the message immediately preceding and more than one addressee. Such
2164 runs of messages may be generated when copies of a message addressed
2165 to multiple users are delivered to a multidrop box.
2167 .SS Header vs. Envelope addresses
2168 The fundamental problem is that by having your mailserver toss several
2169 peoples' mail in a single maildrop box, you may have thrown away
2170 potentially vital information about who each piece of mail was
2171 actually addressed to (the 'envelope address', as opposed to the
2172 header addresses in the RFC822 To/Cc headers - the Bcc is not available
2173 at the receiving end). This 'envelope address' is the address you need
2174 in order to reroute mail properly.
2178 can deduce the envelope address. If the mailserver MTA is
2180 and the item of mail had just one recipient, the MTA will have written
2181 a 'by/for' clause that gives the envelope addressee into its Received
2182 header. But this doesn't work reliably for other MTAs, nor if there is
2183 more than one recipient. By default, \fIfetchmail\fR looks for
2184 envelope addresses in these lines; you can restore this default with
2185 \&\-E "Received" or \&'envelope Received'.
2187 .B As a better alternative,
2188 some SMTP listeners and/or mail servers insert a header
2189 in each message containing a copy of the envelope addresses. This
2190 header (when it exists) is often 'X\-Original\-To', 'Delivered\-To' or
2191 'X\-Envelope\-To'. Fetchmail's assumption about this can be changed with
2192 the \-E or 'envelope' option. Note that writing an envelope header of
2193 this kind exposes the names of recipients (including blind-copy
2194 recipients) to all receivers of the messages, so the upstream must store
2195 one copy of the message per recipient to avoid becoming a privacy problem.
2197 Postfix, since version 2.0, writes an X\-Original\-To: header which
2198 contains a copy of the envelope as it was received.
2200 Qmail and Postfix generally write a 'Delivered\-To' header upon
2201 delivering the message to the mail spool and use it to avoid mail loops.
2202 Qmail virtual domains however will prefix the user name with a string
2203 that normally matches the user's domain. To remove this prefix you can
2204 use the \-Q or 'qvirtual' option.
2206 Sometimes, unfortunately, neither of these methods works. That is the
2207 point when you should contact your ISP and ask them to provide such an
2208 envelope header, and you should not use multidrop in this situation.
2209 When they all fail, fetchmail must fall back on the contents of To/Cc
2210 headers (Bcc headers are not available - see below) to try to determine
2211 recipient addressees -- and these are unreliable.
2212 In particular, mailing-list software often ships mail with only
2213 the list broadcast address in the To header.
2215 .B Note that a future version of fetchmail may remove To/Cc parsing!
2219 cannot deduce a recipient address that is local, and the intended
2220 recipient address was anyone other than fetchmail's invoking user,
2221 .B mail will get lost.
2222 This is what makes the multidrop feature risky without proper envelope
2225 A related problem is that when you blind-copy a mail message, the Bcc
2226 information is carried \fIonly\fR as envelope address (it's removed from
2227 the headers by the sending mail server, so fetchmail can see it only if
2228 there is an X-\Envelope\-To header). Thus, blind-copying to someone who
2229 gets mail over a fetchmail multidrop link will fail unless the the
2230 mailserver host routinely writes X\-Envelope\-To or an equivalent header
2231 into messages in your maildrop.
2233 \fBIn conclusion, mailing lists and Bcc'd mail can only work if the
2234 server you're fetching from (1) stores one copy of the message per
2235 recipient in \fBIyour\fP domain and (2) records the envelope
2236 information in a special header (X\-Original\-To, Delivered\-To,
2237 X\-Envelope\-To).\fR
2239 .SS Good Ways To Use Multidrop Mailboxes
2240 Multiple local names can be used to administer a mailing list from the
2241 client side of a \fIfetchmail\fR collection. Suppose your name is
2242 \&'esr', and you want to both pick up your own mail and maintain a mailing
2243 list called (say) "fetchmail-friends", and you want to keep the alias
2244 list on your client machine.
2246 On your server, you can alias \&'fetchmail\-friends' to 'esr'; then, in
2247 your \fI.fetchmailrc\fR, declare \&'to esr fetchmail\-friends here'.
2248 Then, when mail including 'fetchmail\-friends' as a local address
2249 gets fetched, the list name will be appended to the list of
2250 recipients your SMTP listener sees. Therefore it will undergo alias
2251 expansion locally. Be sure to include 'esr' in the local alias
2252 expansion of fetchmail\-friends, or you'll never see mail sent only to
2253 the list. Also be sure that your listener has the "me-too" option set
2254 (sendmail's \-oXm command-line option or OXm declaration) so your name
2255 isn't removed from alias expansions in messages you send.
2257 This trick is not without its problems, however. You'll begin to see
2258 this when a message comes in that is addressed only to a mailing list
2259 you do \fInot\fR have declared as a local name. Each such message
2260 will feature an 'X\-Fetchmail\-Warning' header which is generated
2261 because fetchmail cannot find a valid local name in the recipient
2262 addresses. Such messages default (as was described above) to being
2263 sent to the local user running
2265 but the program has no way to know that that's actually the right thing.
2267 .SS Bad Ways To Abuse Multidrop Mailboxes
2268 Multidrop mailboxes and
2270 serving multiple users in daemon mode do not mix. The problem, again, is
2271 mail from mailing lists, which typically does not have an individual
2272 recipient address on it. Unless
2274 can deduce an envelope address, such mail will only go to the account
2275 running fetchmail (probably root). Also, blind-copied users are very
2276 likely never to see their mail at all.
2278 If you're tempted to use
2280 to retrieve mail for multiple users from a single mail drop via POP or
2281 IMAP, think again (and reread the section on header and envelope
2282 addresses above). It would be smarter to just let the mail sit in the
2283 mailserver's queue and use fetchmail's ETRN or ODMR modes to trigger
2284 SMTP sends periodically (of course, this means you have to poll more
2285 frequently than the mailserver's expiry period). If you can't arrange
2286 this, try setting up a UUCP feed.
2288 If you absolutely \fImust\fR use multidrop for this purpose, make sure
2289 your mailserver writes an envelope-address header that fetchmail can
2290 see. Otherwise you \fIwill\fR lose mail and it \fIwill\fR come back
2293 .SS Speeding Up Multidrop Checking
2294 Normally, when multiple users are declared
2296 extracts recipient addresses as described above and checks each host
2297 part with DNS to see if it's an alias of the mailserver. If so, the
2298 name mappings described in the "to ... here" declaration are done and
2299 the mail locally delivered.
2301 This is a convenient but also slow method. To speed
2302 it up, pre-declare mailserver aliases with 'aka'; these are checked
2303 before DNS lookups are done. If you're certain your aka list contains
2305 DNS aliases of the mailserver (and all MX names pointing at it - note
2306 this may change in a future version)
2307 you can declare 'no dns' to suppress DNS lookups entirely and
2308 \fIonly\fR match against the aka list.
2311 To facilitate the use of
2313 in shell scripts, an exit code is returned to give an indication
2314 of what occurred during a given connection.
2316 The exit codes returned by
2320 One or more messages were successfully retrieved (or, if the \-c option
2321 was selected, were found waiting but not retrieved).
2323 There was no mail awaiting retrieval. (There may have been old mail still
2324 on the server but not selected for retrieval.)
2326 An error was encountered when attempting to open a socket to retrieve
2327 mail. If you don't know what a socket is, don't worry about it --
2328 just treat this as an 'unrecoverable error'. This error can also be
2329 because a protocol fetchmail wants to use is not listed in /etc/services.
2331 The user authentication step failed. This usually means that a bad
2332 user-id, password, or APOP id was specified. Or it may mean that you
2333 tried to run fetchmail under circumstances where it did not have
2334 standard input attached to a terminal and could not prompt for a
2337 Some sort of fatal protocol error was detected.
2339 There was a syntax error in the arguments to
2342 The run control file had bad permissions.
2344 There was an error condition reported by the server. Can also
2347 timed out while waiting for the server.
2349 Client-side exclusion error. This means
2351 either found another copy of itself already running, or failed in such
2352 a way that it isn't sure whether another copy is running.
2354 The user authentication step failed because the server responded "lock
2355 busy". Try again after a brief pause! This error is not implemented
2356 for all protocols, nor for all servers. If not implemented for your
2357 server, "3" will be returned instead, see above. May be returned when
2358 talking to qpopper or other servers that can respond with "lock busy"
2359 or some similar text containing the word "lock".
2363 run failed while trying to do an SMTP port open or transaction.
2365 Fatal DNS error. Fetchmail encountered an error while performing
2366 a DNS lookup at startup and could not proceed.
2368 BSMTP batch file could not be opened.
2370 Poll terminated by a fetch limit (see the \-\-fetchlimit option).
2372 Server busy indication.
2374 Server timed out during an IMAP IDLE.
2376 Internal error. You should see a message on standard error with
2381 queries more than one host, return status is 0 if \fIany\fR query
2382 successfully retrieved mail. Otherwise the returned error status is
2383 that of the last host queried.
2388 default run control file
2391 default location of file associating hosts with last message IDs seen
2392 (used only with newer RFC1939-compliant POP3 servers supporting the
2396 lock file to help prevent concurrent runs (non-root mode).
2399 your FTP run control file, which (if present) will be searched for
2400 passwords as a last resort before prompting for one interactively.
2402 /var/run/fetchmail.pid
2403 lock file to help prevent concurrent runs (root mode, Linux systems).
2406 lock file to help prevent concurrent runs (root mode, systems without /var/run).
2409 If the FETCHMAILUSER variable is set, it is used as the name of the
2410 calling user (default local name) for purposes such as mailing error
2411 notifications. Otherwise, if either the LOGNAME or USER variable is
2412 correctly set (e.g. the corresponding UID matches the session user ID)
2413 then that name is used as the default local name. Otherwise
2414 \fBgetpwuid\fR(3) must be able to retrieve a password entry for the
2415 session ID (this elaborate logic is designed to handle the case of
2416 multiple names per userid gracefully).
2418 If the environment variable FETCHMAILHOME is set to a valid and
2419 existing directory name, the .fetchmailrc and .fetchids and
2420 \&.fetchmail.pid files are put there instead of in the invoking user's
2421 home directory (and lose the leading dots on their names). The
2422 \&.netrc file is looked for in the the invoking user's home directory
2423 regardless of FETCHMAILHOME's setting.
2425 If the HOME_ETC variable is set, file $HOME_ETC/.fetchmailrc is used
2426 instead of ~/.fetchmailrc.
2431 daemon is running as root, SIGHUP wakes it up from its sleep phase and
2432 forces a poll of all non-skipped servers (this is in accordance with
2433 the usual conventions for system daemons).
2437 is running in daemon mode as non-root, use SIGUSR1 to wake it (this is
2438 so SIGHUP due to logout can retain the default action of killing it).
2442 in foreground while a background fetchmail is running will do
2443 whichever of these is appropriate to wake it up.
2445 .SH BUGS AND KNOWN PROBLEMS
2447 The assumptions that the DNS and in particular the checkalias options
2448 make are not often sustainable. For instance, it has become uncommon for
2449 an MX server to be a POP3 or IMAP server at the same time. Therefore the
2450 MX lookups may go away in a future release.
2452 The mda and plugin options interact badly. In order to collect error
2453 status from the MDA, fetchmail has to change its normal signal
2454 handling so that dead plugin processes don't get reaped until the end
2455 of the poll cycle. This can cause resource starvation if too many
2456 zombies accumulate. So either don't deliver to a MDA using plugins or
2457 risk being overrun by an army of undead.
2459 The \-\-interface option does not support IPv6 and it is doubtful if it
2460 ever will, since there is no portable way to query interface IPv6
2463 The RFC822 address parser used in multidrop mode chokes on some
2464 @-addresses that are technically legal but bizarre. Strange uses of
2465 quoting and embedded comments are likely to confuse it.
2467 In a message with multiple envelope headers, only the last one
2468 processed will be visible to fetchmail.
2470 Use of some of these protocols requires that the program send
2471 unencrypted passwords over the TCP/IP connection to the mailserver.
2472 This creates a risk that name/password pairs might be snaffled with a
2473 packet sniffer or more sophisticated monitoring software. Under Linux
2474 and FreeBSD, the \-\-interface option can be used to restrict polling to
2475 availability of a specific interface device with a specific local or
2476 remote IP address, but snooping is still possible if (a) either host
2477 has a network device that can be opened in promiscuous mode, or (b)
2478 the intervening network link can be tapped. We recommend the use of
2480 tunnelling to not only shroud your passwords but encrypt the entire
2483 Use of the %F or %T escapes in an mda option could open a security
2484 hole, because they pass text manipulable by an attacker to a shell
2485 command. Potential shell characters are replaced by '_' before
2486 execution. The hole is further reduced by the fact that fetchmail
2487 temporarily discards any suid privileges it may have while running the
2488 MDA. For maximum safety, however, don't use an mda command containing
2489 %F or %T when fetchmail is run from the root account itself.
2491 Fetchmail's method of sending bounces due to errors or spam-blocking and
2492 spam bounces requires that port 25 of localhost be available for sending
2497 while a background instance is running and break the syntax, the
2498 background instance will die silently. Unfortunately, it can't
2499 die noisily because we don't yet know whether syslog should be enabled.
2500 On some systems, fetchmail dies quietly even if there is no syntax
2501 error; this seems to have something to do with buggy terminal ioctl
2504 The \-f\~\- option (reading a configuration from stdin) is incompatible
2505 with the plugin option.
2507 The 'principal' option only handles Kerberos IV, not V.
2509 Interactively entered passwords are truncated after 63 characters. If
2510 you really need to use a longer password, you will have to use a
2513 A backslash as the last character of a configuration file will be
2514 flagged as a syntax error rather than ignored.
2516 Send comments, bug reports, gripes, and the like to the
2517 fetchmail\-devel list <fetchmail\-devel@lists.berlios.de>. An HTML FAQ is
2518 available at the fetchmail home page; surf to
2519 http://fetchmail.berlios.de/ or do a WWW search for pages with
2520 \&'fetchmail' in their titles.
2523 Fetchmail is currently maintained by Matthias Andree and Rob Funk with
2524 major assistance from Sunil Shetye (for code) and Rob MacGregor (for the
2527 Most of the code is from Eric S. Raymond <esr@snark.thyrsus.com>. Too
2528 many other people to name here have contributed code and patches.
2530 This program is descended from and replaces
2532 by Carl Harris <ceharris@mal.com>; the internals have become quite different,
2533 but some of its interface design is directly traceable to that
2536 This manual page has been improved by R.\ Hannes Beinert and Héctor
2540 mutt(1), elm(1), mail(1), sendmail(8), popd(8), imapd(8), netrc(5)
2542 The fetchmail home page: <http://fetchmail.berlios.de/>
2544 The maildrop home page: <http://www.courier-mta.org/maildrop/>
2545 .SH APPLICABLE STANDARDS
2548 RFC 821, RFC2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC 1985,
2552 RFC 822, RFC2822, RFC 1123, RFC 1892, RFC 1894.
2558 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC1734, RFC 1939, RFC 1957,
2562 RFC 1460, RFC 1725, RFC 1939.
2571 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC 2177,
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