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.
8 .TH fetchmail 1 "fetchmail 6.3.5" "fetchmail" "fetchmail reference manual"
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
176 .B \-a | \-\-all | (since v6.3.3) \-\-fetchall
177 (Keyword: fetchall, since v3.0)
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
183 or ODMR. While the \-a and \-\-all command-line and fetchall rcfile
184 options have been supported for a long time, the \-\-fetchall
185 command-line option was added in v6.3.3.
189 Keep retrieved messages on the remote mailserver. Normally, messages
190 are deleted from the folder on the mailserver after they have been retrieved.
193 option causes retrieved messages to remain in your folder on the
194 mailserver. This option does not work with ETRN or ODMR.
198 Delete retrieved messages from the remote mailserver. This
199 option forces retrieved mail to be deleted. It may be useful if
200 you have specified a default of \fBkeep\fR in your
201 \&\fI.fetchmailrc\fR. This option is forced on with ETRN and ODMR.
204 POP3/IMAP only. This is a dangerous option and can cause mail loss when
205 used improperly. It deletes old (seen) messages from the mailserver
206 before retrieving new messages. \fBWarning:\fR This can cause mail loss if
207 you check your mail with other clients than fetchmail, and cause
208 fetchmail to delete a message it had never fetched before. It can also
209 cause mail loss if the mail server marks the message seen after
210 retrieval (IMAP2 servers). You should probably not use this option in your
211 configuration file. If you use it with POP3, you must use the 'uidl'
212 option. What you probably want is the default setting: if you don't
213 specify '\-k', then fetchmail will automatically delete messages after
217 POP3/IMAP only, since version 6.3.0. Delete oversized messages from the
218 mailserver before retrieving new messages. The size limit should be
219 separately specified with the \-\-limit option. This option does not
220 work with ETRN or ODMR.
221 .SS Protocol and Query Options
223 .B \-p <proto> | \-\-proto <proto> | \-\-protocol <proto>
224 (Keyword: proto[col])
225 Specify the protocol to use when communicating with the remote
226 mailserver. If no protocol is specified, the default is AUTO.
228 may be one of the following:
231 Tries IMAP, POP3, and POP2 (skipping any of these for which support
232 has not been compiled in).
234 Post Office Protocol 2 (legacy, to be removed from future release)
236 Post Office Protocol 3
238 Use POP3 with old-fashioned MD5-challenge authentication.
240 Use POP3 with RPOP authentication.
242 Use POP3 with Kerberos V4 authentication on port 1109.
244 Use POP3 with Demon Internet's SDPS extensions.
246 IMAP2bis, IMAP4, or IMAP4rev1 (\fIfetchmail\fR automatically detects their capabilities).
248 Use the ESMTP ETRN option.
250 Use the the On-Demand Mail Relay ESMTP profile.
253 All these alternatives work in basically the same way (communicating
254 with standard server daemons to fetch mail already delivered to a
255 mailbox on the server) except ETRN and ODMR. The ETRN mode
256 allows you to ask a compliant ESMTP server (such as BSD sendmail at
257 release 8.8.0 or higher) to immediately open a sender-SMTP connection
258 to your client machine and begin forwarding any items addressed to
259 your client machine in the server's queue of undelivered mail. The
260 ODMR mode requires an ODMR-capable server and works similarly to
261 ETRN, except that it does not require the client machine to have
266 Force UIDL use (effective only with POP3). Force client-side tracking
267 of 'newness' of messages (UIDL stands for "unique ID listing" and is
268 described in RFC1939). Use with 'keep' to use a mailbox as a baby
269 news drop for a group of users. The fact that seen messages are skipped
270 is logged, unless error logging is done through syslog while running in
271 daemon mode. Note that fetchmail may automatically enable this option
272 depending on upstream server capabilities. Note also that this option
273 may be removed and forced enabled in a future fetchmail version. See
276 .B \-\-idle (since 6.3.3)
277 (Keyword: idle, since before 6.0.0)
278 Enable IDLE use (effective only with IMAP). Note that this works with
279 only one folder at a given time. While the idle rcfile keyword had been
280 supported for a long time, the \-\-idle command-line option was added in
281 version 6.3.3. IDLE use means that fetchmail tells the IMAP server to
282 send notice of new messages, so they can be retrieved sooner than would
283 be possible with regular polls.
285 .B \-P <portnumber> | \-\-service <servicename>
286 (Keyword: service) Since version 6.3.0.
287 The service option permits you to specify a service name to connect to.
288 You can specify a decimal port number here, if your services database
289 lacks the required service-port assignments. See the FAQ item R12 and
290 the \-\-ssl documentation for details. This replaces the older \-\-port
293 .B \-\-port <portnumber>
295 Obsolete version of \-\-service that does not take service names.
297 this option may be removed from a future version.
299 .B \-\-principal <principal>
301 The principal option permits you to specify a service principal for
302 mutual authentication. This is applicable to POP3 or IMAP with Kerberos
305 .B \-t <seconds> | \-\-timeout <seconds>
307 The timeout option allows you to set a server-nonresponse
308 timeout in seconds. If a mailserver does not send a greeting message
309 or respond to commands for the given number of seconds,
310 \fIfetchmail\fR will hang up on it. Without such a timeout
311 \fIfetchmail\fR might hang up indefinitely trying to fetch mail from a
312 down host. This would be particularly annoying for a \fIfetchmail\fR
313 running in background. There is a default timeout which fetchmail\~\-V
314 will report. If a given connection receives too many timeouts in
315 succession, fetchmail will consider it wedged and stop retrying,
316 the calling user will be notified by email if this happens.
318 .B \-\-plugin <command>
319 (Keyword: plugin) The plugin option allows you to use an external
320 program to establish the TCP connection. This is useful if you want
321 to use socks, SSL, ssh, or need some special firewalling setup. The
322 program will be looked up in $PATH and can optionally be passed the
323 hostname and port as arguments using "%h" and "%p" respectively (note
324 that the interpolation logic is rather primitive, and these token must
325 be bounded by whitespace or beginning of string or end of string).
326 Fetchmail will write to the plugin's stdin and read from the plugin's
329 .B \-\-plugout <command>
331 Identical to the plugin option above, but this one is used for the SMTP
332 connections (which will probably not need it, so it has been separated
335 .B \-r <name> | \-\-folder <name>
337 Causes a specified non-default mail folder on the mailserver (or
338 comma-separated list of folders) to be retrieved. The syntax of the
339 folder name is server-dependent. This option is not available under
343 (Keyword: tracepolls)
344 Tell fetchmail to poll trace information in the form 'polling %s
345 account %s' and 'folder %s' to the Received line it generates,
346 where the %s parts are replaced by the user's remote name, the poll
347 label, and the folder (mailbox) where available (the Received header
348 also normally includes the server's true name). This can be used to
349 facilitate mail filtering based on the account it is being received
350 from. The folder information is written only since version 6.3.4.
354 Causes the connection to the mail server to be encrypted via SSL. Connect
355 to the server using the specified base protocol over a connection secured
356 by SSL. SSL support must be present at the server.
358 Note that fetchmail may still try to negotiate TLS even if this option
359 is not given. You can use the \-\-sslproto option to defeat this
360 behavior or tell fetchmail to negotiate a particular SSL protocol.
362 If no port is specified, the connection is attempted to the well known
363 port of the SSL version of the base protocol. This is generally a
364 different port than the port used by the base protocol. For IMAP, this
365 is port 143 for the clear protocol and port 993 for the SSL secured
366 protocol, for POP3, it is port 110 for the clear text and port 995 for
367 the encrypted variant.
369 If your system lacks the corresponding entries from /etc/services, see
370 the \-\-service option and specify the numeric port number as given in
371 the previous paragraph (unless your ISP had directed you to different
372 ports, which is uncommon however).
374 .B \-\-sslcert <name>
376 Specifies the file name of the client side public SSL certificate. Some
377 SSL encrypted servers may require client side keys and certificates for
378 authentication. In most cases, this is optional. This specifies
379 the location of the public key certificate to be presented to the server
380 at the time the SSL session is established. It is not required (but may
381 be provided) if the server does not require it. Some servers may
382 require it, some servers may request it but not require it, and some
383 servers may not request it at all. It may be the same file
384 as the private key (combined key and certificate file) but this is not
389 Specifies the file name of the client side private SSL key. Some SSL
390 encrypted servers may require client side keys and certificates for
391 authentication. In most cases, this is optional. This specifies
392 the location of the private key used to sign transactions with the server
393 at the time the SSL session is established. It is not required (but may
394 be provided) if the server does not require it. Some servers may
395 require it, some servers may request it but not require it, and some
396 servers may not request it at all. It may be the same file
397 as the public key (combined key and certificate file) but this is not
398 recommended. If a password is required to unlock the key, it will be
399 prompted for at the time just prior to establishing the session to the
400 server. This can cause some complications in daemon mode.
402 .B \-\-sslproto <name>
404 Forces an SSL protocol. Possible values are '\fBssl2\fR',
405 \&'\fBssl3\fR', '\fBssl23\fR', and '\fBtls1\fR'. Try this if the default
406 handshake does not work for your server. To defeat automatic TLSv1
407 negotiation when the server advertises STARTTLS or STLS, use \fB''\fR or
408 \&'\fBssl23\fR'. The default is to try appropriate protocols depending
413 Causes fetchmail to strictly check the server certificate against a set of
414 local trusted certificates (see the \fBsslcertpath\fR option). If the server
415 certificate is not signed by one of the trusted ones (directly or indirectly),
416 the SSL connection will fail, regardless of the \fBsslfingerprint\fR
417 option. This checking should prevent man-in-the-middle attacks against
418 the SSL connection. Note that CRLs are seemingly not currently supported
419 by OpenSSL in certificate verification! Your system clock should be
420 reasonably accurate when using this option.
422 Note that this optional behavior may become default behavior in future
425 .B \-\-sslcertpath <directory>
426 (Keyword: sslcertpath)
427 Sets the directory fetchmail uses to look up local certificates. The default
428 is your OpenSSL default one. The directory must be hashed as OpenSSL expects
429 it - every time you add or modify a certificate in the directory, you need
430 to use the \fBc_rehash\fR tool (which comes with OpenSSL in the tools/
433 .B \-\-sslfingerprint <fingerprint>
434 (Keyword: sslfingerprint)
435 Specify the fingerprint of the server key (an MD5 hash of the key) in
436 hexadecimal notation with colons separating groups of two digits. The letter
437 hex digits must be in upper case. This is the default format OpenSSL uses,
438 and the one fetchmail uses to report the fingerprint when an SSL connection
439 is established. When this is specified, fetchmail will compare the server key
440 fingerprint with the given one, and the connection will fail if they do not
441 match regardless of the \fBsslcertck\fR setting.
442 This can be used to prevent man-in-the-middle attacks, but the finger
443 print from the server needs to be obtained or verified over a secure
444 channel, and certainly not over the same Internet connection that
447 Using this option will prevent printing certificate verification errors
448 as long as \-\-sslcertck is unset.
450 To obtain the fingerprint of a certificate stored in the file cert.pem,
454 openssl x509 \-in cert.pem \-noout \-md5 \-fingerprint
459 .SS Delivery Control Options
461 .B \-S <hosts> | \-\-smtphost <hosts>
462 (Keyword: smtp[host])
463 Specify a hunt list of hosts to forward mail to (one or more
464 hostnames, comma-separated). Hosts are tried in list order; the first
465 one that is up becomes the forwarding target for the current run. If
466 this option is not specified, 'localhost' is used as the default.
467 Each hostname may have a port number following the host name. The
468 port number is separated from the host name by a slash; the default
469 port is "smtp". If you specify an absolute path name (beginning with
470 a /), it will be interpreted as the name of a UNIX socket accepting
471 LMTP connections (such as is supported by the Cyrus IMAP daemon)
475 \-\-smtphost server1,server2/2525,server3,/var/imap/socket/lmtp
478 This option can be used with ODMR, and will make fetchmail a relay
479 between the ODMR server and SMTP or LMTP receiver.
481 .B \-\-fetchdomains <hosts>
482 (Keyword: fetchdomains)
483 In ETRN or ODMR mode, this option specifies the list of domains the
484 server should ship mail for once the connection is turned around. The
485 default is the FQDN of the machine running
488 .B \-D <domain> | \-\-smtpaddress <domain>
489 (Keyword: smtpaddress) Specify the domain to be appended to addresses
490 in RCPT TO lines shipped to SMTP. When this is not specified, the name
491 of the SMTP server (as specified by \-\-smtphost) is used for SMTP/LMTP
492 and 'localhost' is used for UNIX socket/BSMTP.
494 .B \-\-smtpname <user@domain>
496 Specify the domain and user to be put in RCPT TO lines shipped to SMTP.
497 The default user is the current local user.
499 .B \-Z <nnn> | \-\-antispam <nnn[, nnn]...>
501 Specifies the list of numeric SMTP errors that are to be interpreted
502 as a spam-block response from the listener. A value of \-1 disables
503 this option. For the command-line option, the list values should
506 .B \-m <command> | \-\-mda <command>
507 (Keyword: mda) You can force mail to be passed to an MDA directly
508 (rather than forwarded to port 25) with the \-\-mda or \-m option. To
509 avoid losing mail, use this option only with MDAs like maildrop or
510 MTAs like sendmail that return a nonzero status on disk-full and other
511 resource-exhaustion errors; the nonzero status tells fetchmail that
512 delivery failed and prevents the message from being deleted off the
513 server. If \fIfetchmail\fR is running as root, it sets its user id to
514 that of the target user while delivering mail through an MDA. Some
515 possible MDAs are "/usr/sbin/sendmail \-i \-f %F \-\- %T" (\fBNote:\fR
516 some several older or vendor sendmail versions mistake \-\- for an
517 address, rather than an indicator to mark the end of the option arguments),
518 "/usr/bin/deliver" and "/usr/bin/maildrop \-d %T". Local delivery
519 addresses will be inserted into the MDA command wherever you place a
520 %T; the mail message's From address will be inserted where you place
521 an %F. \fBDO NOT ENCLOSE THE %F OR %T STRING IN SINGLE QUOTES!\fR For
522 both %T and %F, fetchmail encloses the addresses in single quotes ('),
523 after removing any single quotes they may contain, before the MDA
524 command is passed to the shell. Do \fINOT\fR use an MDA invocation
525 like "sendmail \-i \-t" that dispatches on the contents of To/Cc/Bcc, it
526 will create mail loops and bring the just wrath of many postmasters
527 down upon your head. Also, do \fInot\fR try to combine multidrop
528 mode with an MDA such as maildrop or procmail that can only accept one
529 address; you will lose mail.
531 A word of warning: the well-known
533 package is very hard to configure properly, it has a very nasty "fall
534 through to the next rule" behavior on delivery errors (even temporary
535 ones, such as out of disk space if another user's mail daemon copies the
536 mailbox around to purge old messages), so your mail will end up in the
537 wrong mailbox sooner or later. The proper procmail configuration is
538 outside the scope of this document though. Using
540 is usually much easier, and many users find the filter syntax used by
541 maildrop easier to understand.
546 Cause delivery via LMTP (Local Mail Transfer Protocol). A service
547 host and port \fBmust\fR be explicitly specified on each host in the
548 smtphost hunt list (see above) if this option is selected; the default
549 port 25 will (in accordance with RFC 2033) not be accepted.
551 .B \-\-bsmtp <filename>
553 Append fetched mail to a BSMTP file. This simply contains the SMTP
554 commands that would normally be generated by fetchmail when passing
555 mail to an SMTP listener daemon. An argument of '\-' causes the mail
556 to be written to standard output. Note that fetchmail's
557 reconstruction of MAIL FROM and RCPT TO lines is not guaranteed
558 correct; the caveats discussed under THE USE AND ABUSE OF MULTIDROP
559 MAILBOXES below apply.
560 .SS Resource Limit Control Options
562 .B \-l <maxbytes> | \-\-limit <maxbytes>
563 (Keyword: limit) Takes a maximum octet size argument. Messages larger
564 than this size will not be fetched and will be left on the server (in
565 foreground sessions, the progress messages will note that they are
566 "oversized"). If the fetch protocol permits (in particular, under
567 IMAP or POP3 without the fetchall option) the message will not be
570 An explicit \-\-limit of 0 overrides any limits set in your
571 run control file. This option is intended for those needing to
572 strictly control fetch time due to expensive and variable phone rates.
574 Combined with \-\-limitflush, it can be used to delete oversized
575 messages waiting on a server. In daemon mode, oversize notifications
576 are mailed to the calling user (see the \-\-warnings option). This
577 option does not work with ETRN or ODMR.
579 .B \-w <interval> | \-\-warnings <interval>
581 Takes an interval in seconds. When you call
583 with a 'limit' option in daemon mode, this controls the interval at
584 which warnings about oversized messages are mailed to the calling user
585 (or the user specified by the 'postmaster' option). One such
586 notification is always mailed at the end of the the first poll that
587 the oversized message is detected. Thereafter, re-notification is
588 suppressed until after the warning interval elapses (it will take
589 place at the end of the first following poll).
591 .B \-b <count> | \-\-batchlimit <count>
592 (Keyword: batchlimit)
593 Specify the maximum number of messages that will be shipped to an SMTP
594 listener before the connection is deliberately torn down and rebuilt
595 (defaults to 0, meaning no limit). An explicit \-\-batchlimit of 0
596 overrides any limits set in your run control file. While
597 \fBsendmail\fR(8) normally initiates delivery of a message immediately
598 after receiving the message terminator, some SMTP listeners are not so
599 prompt. MTAs like \fIsmail\fR(8) may wait till the
600 delivery socket is shut down to deliver. This may produce annoying
601 delays when \fIfetchmail\fR is processing very large batches. Setting
602 the batch limit to some nonzero size will prevent these delays. This
603 option does not work with ETRN or ODMR.
605 .B \-B <number> | \-\-fetchlimit <number>
606 (Keyword: fetchlimit)
607 Limit the number of messages accepted from a given server in a single
608 poll. By default there is no limit. An explicit \-\-fetchlimit of 0
609 overrides any limits set in your run control file.
610 This option does not work with ETRN or ODMR.
612 .B \-\-fetchsizelimit <number>
613 (Keyword: fetchsizelimit)
614 Limit the number of sizes of messages accepted from a given server in
615 a single transaction. This option is useful in reducing the delay in
616 downloading the first mail when there are too many mails in the
617 mailbox. By default, the limit is 100. If set to 0, sizes of all
618 messages are downloaded at the start.
619 This option does not work with ETRN or ODMR. For POP3, the only valid
622 .B \-\-fastuidl <number>
624 Do a binary instead of linear search for the first unseen UID. Binary
625 search avoids downloading the UIDs of all mails. This saves time
626 (especially in daemon mode) where downloading the same set of UIDs in
627 each poll is a waste of bandwidth. The number 'n' indicates how rarely
628 a linear search should be done. In daemon mode, linear search is used
629 once followed by binary searches in 'n-1' polls if 'n' is greater than
630 1; binary search is always used if 'n' is 1; linear search is always
631 used if 'n' is 0. In non-daemon mode, binary search is used if 'n' is
632 1; otherwise linear search is used. The default value of 'n' is 4.
633 This option works with POP3 only.
635 .B \-e <count> | \-\-expunge <count>
637 Arrange for deletions to be made final after a given number of
638 messages. Under POP2 or POP3, fetchmail cannot make deletions final
639 without sending QUIT and ending the session -- with this option on,
640 fetchmail will break a long mail retrieval session into multiple
641 sub-sessions, sending QUIT after each sub-session. This is a good
642 defense against line drops on POP3 servers that do not do the
643 equivalent of a QUIT on hangup. Under IMAP,
645 normally issues an EXPUNGE command after each deletion in order to
646 force the deletion to be done immediately. This is safest when your
647 connection to the server is flaky and expensive, as it avoids
648 resending duplicate mail after a line hit. However, on large
649 mailboxes the overhead of re-indexing after every message can slam the
650 server pretty hard, so if your connection is reliable it is good to do
651 expunges less frequently. Also note that some servers enforce a delay
652 of a few seconds after each quit, so fetchmail may not be able to get
653 back in immediately after an expunge -- you may see "lock busy" errors
654 if this happens. If you specify this option to an integer N,
657 to only issue expunges on every Nth delete. An argument of zero
658 suppresses expunges entirely (so no expunges at all will be done until
659 the end of run). This option does not work with ETRN or ODMR.
660 .SS Authentication Options
662 .B \-u <name> | \-\-user <name> | \-\-username <name>
663 (Keyword: user[name])
664 Specifies the user identification to be used when logging in to the mailserver.
665 The appropriate user identification is both server and user-dependent.
666 The default is your login name on the client machine that is running
668 See USER AUTHENTICATION below for a complete description.
670 .B \-I <specification> | \-\-interface <specification>
672 Require that a specific interface device be up and have a specific local
673 or remote IPv4 (IPv6 is not supported by this option yet) address (or
674 range) before polling. Frequently \fIfetchmail\fP
675 is used over a transient point-to-point TCP/IP link established directly
676 to a mailserver via SLIP or PPP. That is a relatively secure channel.
677 But when other TCP/IP routes to the mailserver exist (e.g. when the link
678 is connected to an alternate ISP), your username and password may be
679 vulnerable to snooping (especially when daemon mode automatically polls
680 for mail, shipping a clear password over the net at predictable
681 intervals). The \-\-interface option may be used to prevent this. When
682 the specified link is not up or is not connected to a matching IP
683 address, polling will be skipped. The format is:
686 interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]
689 The field before the first slash is the interface name (i.e. sl0, ppp0
690 etc.). The field before the second slash is the acceptable IP address.
691 The field after the second slash is a mask which specifies a range of
692 IP addresses to accept. If no mask is present 255.255.255.255 is
693 assumed (i.e. an exact match). This option is currently only supported
694 under Linux and FreeBSD. Please see the
696 section for below for FreeBSD specific information.
698 Note that this option may be removed from a future fetchmail version.
700 .B \-M <interface> | \-\-monitor <interface>
702 Daemon mode can cause transient links which are automatically taken down
703 after a period of inactivity (e.g. PPP links) to remain up
704 indefinitely. This option identifies a system TCP/IP interface to be
705 monitored for activity. After each poll interval, if the link is up but
706 no other activity has occurred on the link, then the poll will be
707 skipped. However, when fetchmail is woken up by a signal, the
708 monitor check is skipped and the poll goes through unconditionally.
709 This option is currently only supported under Linux and FreeBSD.
714 options to work for non root users under FreeBSD, the fetchmail binary
715 must be installed SGID kmem. This would be a security hole, but
716 fetchmail runs with the effective GID set to that of the kmem group
718 when interface data is being collected.
720 Note that this option may be removed from a future fetchmail version.
723 (Keyword: auth[enticate])
724 This option permits you to specify an authentication type (see USER
725 AUTHENTICATION below for details). The possible values are \fBany\fR,
726 \&\fBpassword\fR, \fBkerberos_v5\fR, \fBkerberos\fR (or, for
727 excruciating exactness, \fBkerberos_v4\fR), \fBgssapi\fR,
728 \fBcram\-md5\fR, \fBotp\fR, \fBntlm\fR, \fBmsn\fR (only for POP3) and
729 \fBssh\fR. When \fBany\fR (the default) is specified, fetchmail tries
730 first methods that don't require a password (GSSAPI, KERBEROS\ IV,
731 KERBEROS\ 5); then it looks for methods that mask your password
732 (CRAM-MD5, X\-OTP - note that NTLM and MSN are not autoprobed for POP3
733 and MSN is only supported for POP3); and only if the server doesn't
734 support any of those will it ship your password en clair. Other values
735 may be used to force various authentication methods
736 (\fBssh\fR suppresses authentication and is thus good for IMAP PREAUTH).
737 Any value other than \fBpassword\fR, \fBcram\-md5\fR, \fBntlm\fR,
738 \&\fBmsn\fR or \fBotp\fR suppresses fetchmail's normal inquiry for a
739 password. Specify \fBssh\fR when you are using an end-to-end secure
740 connection such as an ssh tunnel; specify \fBgssapi\fR or
741 \&\fBkerberos_v4\fR if you are using a protocol variant that employs
742 GSSAPI or K4. Choosing KPOP protocol automatically selects Kerberos
743 authentication. This option does not work with ETRN.
744 .SS Miscellaneous Options
746 .B \-f <pathname> | \-\-fetchmailrc <pathname>
747 Specify a non-default name for the
749 run control file. The pathname argument must be either "-" (a single
750 dash, meaning to read the configuration from standard input) or a
751 filename. Unless the \-\-version option is also on, a named file
752 argument must have permissions no more open than 0600 (u=rw,g=,o=) or
755 .B \-i <pathname> | \-\-idfile <pathname>
757 Specify an alternate name for the .fetchids file used to save POP3
758 UIDs. NOTE: since fetchmail 6.3.0, write access to the directory
759 containing the idfile is required, as fetchmail writes a temporary file
760 and renames it into the place of the real idfile only if the temporary
761 file has been written successfully. This avoids the truncation of
762 idfiles when running out of disk space.
764 .B \--pidfile <pathname>
765 (Keyword: pidfile; since fetchmail v6.3.4)
766 Override the default location of the PID file. Default: see
769 .B \-n | \-\-norewrite
770 (Keyword: no rewrite)
773 edits RFC-822 address headers (To, From, Cc, Bcc, and Reply\-To) in
774 fetched mail so that any mail IDs local to the server are expanded to
775 full addresses (@ and the mailserver hostname are appended). This enables
776 replies on the client to get addressed correctly (otherwise your
777 mailer might think they should be addressed to local users on the
778 client machine!). This option disables the rewrite. (This option is
779 provided to pacify people who are paranoid about having an MTA edit
780 mail headers and want to know they can prevent it, but it is generally
781 not a good idea to actually turn off rewrite.)
782 When using ETRN or ODMR, the rewrite option is ineffective.
784 .B \-E <line> | \-\-envelope <line>
785 (Keyword: envelope; Multidrop only)
787 In the configuration file, an enhanced syntax is used:
789 .B envelope [<count>] <line>
791 This option changes the header
793 assumes will carry a copy of the mail's envelope address. Normally
794 this is 'X\-Envelope\-To', but as this header is not standard, practice
795 varies. See the discussion of multidrop address handling below. As a
796 special case, 'envelope "Received"' enables parsing of sendmail-style
797 Received lines. This is the default, and it should not be necessary
798 unless you have globally disabled Received parsing with 'no envelope'
799 in the \fI.fetchmailrc\fR file.
801 The optional count argument (only available in the configuration file)
802 determines how many header lines of this kind are skipped. A count of 1
803 means: skip the first, take the second. A count of 2 means: skip the
804 first and second, take the third, and so on.
806 .B \-Q <prefix> | \-\-qvirtual <prefix>
807 (Keyword: qvirtual; Multidrop only)
808 The string prefix assigned to this option will be removed from the user
809 name found in the header specified with the \fIenvelope\fR option
810 (\fIbefore\fR doing multidrop name mapping or localdomain checking,
811 if either is applicable). This option is useful if you are using
813 to collect the mail for an entire domain and your ISP (or your mail
814 redirection provider) is using qmail.
815 One of the basic features of qmail is the
819 message header. Whenever qmail delivers a message to a local mailbox
820 it puts the username and hostname of the envelope recipient on this
821 line. The major reason for this is to prevent mail loops. To set up
822 qmail to batch mail for a disconnected site the ISP-mailhost will have
823 normally put that site in its 'Virtualhosts' control file so it will
824 add a prefix to all mail addresses for this site. This results in mail
825 .\" The \&@\& tries to stop HTML converters from making a mailto URL here.
826 sent to 'username\&@\&userhost.userdom.dom.com' having a
827 \&'Delivered\-To:' line of the form:
829 Delivered\-To: mbox\-userstr\-username\&@\&userhost.example.com
831 The ISP can make the 'mbox\-userstr\-' prefix anything they choose
832 but a string matching the user host name is likely.
833 By using the option 'envelope Delivered\-To:' you can make fetchmail reliably
834 identify the original envelope recipient, but you have to strip the
835 \&'mbox\-userstr\-' prefix to deliver to the correct user.
836 This is what this option is for.
841 file, interpret any command-line options specified, and dump a
842 configuration report to standard output. The configuration report is
843 a data structure assignment in the language Python. This option
844 is meant to be used with an interactive
852 Removed before version 6.3.0, the required underlying inet6_apps library
853 had been discontinued and is no longer available.
855 .SH USER AUTHENTICATION AND ENCRYPTION
856 All modes except ETRN require authentication of the client to the server.
857 Normal user authentication in
859 is very much like the authentication mechanism of
861 The correct user-id and password depend upon the underlying security
862 system at the mailserver.
864 If the mailserver is a Unix machine on which you have an ordinary user
865 account, your regular login name and password are used with
867 If you use the same login name on both the server and the client machines,
868 you needn't worry about specifying a user-id with the
870 option -- the default behavior is to use your login name on the
871 client machine as the user-id on the server machine. If you use a
872 different login name on the server machine, specify that login name
875 option. e.g. if your login name is 'jsmith' on a machine named 'mailgrunt',
880 fetchmail \-u jsmith mailgrunt
882 The default behavior of
884 is to prompt you for your mailserver password before the connection is
885 established. This is the safest way to use
887 and ensures that your password will not be compromised. You may also specify
888 your password in your
890 file. This is convenient when using
892 in daemon mode or with scripts.
893 .SS Using netrc files
895 If you do not specify a password, and
897 cannot extract one from your
899 file, it will look for a
901 file in your home directory before requesting one interactively; if an
902 entry matching the mailserver is found in that file, the password will
903 be used. Fetchmail first looks for a match on poll name; if it finds none,
904 it checks for a match on via name. See the
906 man page for details of the syntax of the
908 file. To show a practical example, a .netrc might look like
912 machine hermes.example.org
917 You can repeat this block with different user information if you need to
918 provide more than one password.
920 This feature may allow you to avoid duplicating password
921 information in more than one file.
923 On mailservers that do not provide ordinary user accounts, your user-id and
924 password are usually assigned by the server administrator when you apply for
925 a mailbox on the server. Contact your server administrator if you don't know
926 the correct user-id and password for your mailbox account.
929 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
930 independent authentication using the
932 file on the mailserver side. Under this RPOP variant, a fixed
933 per-user ID equivalent to a password was sent in clear over a link to
934 a reserved port, with the command RPOP rather than PASS to alert the
935 server that it should do special checking. RPOP is supported
938 (you can specify 'protocol RPOP' to have the program send 'RPOP'
939 rather than 'PASS') but its use is strongly discouraged, and support
940 will be removed from a future fetchmail version. This
941 facility was vulnerable to spoofing and was withdrawn in RFC1460.
943 RFC1460 introduced APOP authentication. In this variant of POP3,
944 you register an APOP password on your server host (the program
945 to do this with on the server is probably called \fIpopauth\fR(8)). You
946 put the same password in your
950 logs in, it sends a cryptographically secure hash of your password and
951 the server greeting time to the server, which can verify it by
952 checking its authorization database.
955 makes some efforts to make the server believe messages had not been
956 retrieved, by using the TOP command with a large number of lines when
957 possible. TOP is a command that retrieves the full header and
958 a \fIfetchmail\fP-specified amount of body lines. It is optional and
959 therefore not implemented by all servers, and some are known to
960 implement it improperly. On many servers however, the RETR command which
961 retrieves the full message with header and body, sets the "seen" flag
962 (for instance, in a web interface), whereas the TOP command does not do
966 will always use the RETR command if "fetchall" is set.
968 will also use the RETR command if "keep" is set and "uidl" is unset.
971 will use the RETR command on Maillennium POP3/PROXY
972 servers (used by Comcast) to avoid a deliberate TOP misinterpretation in
973 this server that causes message corruption.
977 will use the TOP command. This implies that in "keep" setups, "uidl"
978 must be set if "TOP" is desired.
981 that this description is true for the current version of fetchmail, but
982 the behavior may change in future versions. In particular, fetchmail may
983 prefer the RETR command because the TOP command causes much grief on
984 some servers and is only optional.
985 .SH ALTERNATE AUTHENTICATION FORMS
987 If your \fIfetchmail\fR was built with Kerberos support and you specify
988 Kerberos authentication (either with \-\-auth or the \fI.fetchmailrc\fR
989 option \fBauthenticate kerberos_v4\fR) it will try to get a Kerberos
990 ticket from the mailserver at the start of each query. Note: if
991 either the pollname or via name is 'hesiod', fetchmail will try to use
992 Hesiod to look up the mailserver.
994 If you use POP3 or IMAP with GSSAPI authentication, \fIfetchmail\fR will
995 expect the server to have RFC1731- or RFC1734-conforming GSSAPI
996 capability, and will use it. Currently this has only been tested over
997 Kerberos V, so you're expected to already have a ticket-granting
998 ticket. You may pass a username different from your principal name
999 using the standard \fB\-\-user\fR command or by the \fI.fetchmailrc\fR
1002 If your IMAP daemon returns the PREAUTH response in its greeting line,
1003 fetchmail will notice this and skip the normal authentication step.
1004 This can be useful, e.g. if you start imapd explicitly using ssh.
1005 In this case you can declare the authentication value 'ssh' on that
1006 site entry to stop \fI.fetchmail\fR from asking you for a password
1009 If you are using POP3, and the server issues a one-time-password
1010 challenge conforming to RFC1938, \fIfetchmail\fR will use your
1011 password as a pass phrase to generate the required response. This
1012 avoids sending secrets over the net unencrypted.
1014 Compuserve's RPA authentication (similar to APOP) is supported. If you
1015 compile in the support, \fIfetchmail\fR will try to perform an RPA pass-phrase
1016 authentication instead of sending over the password en clair if it
1017 detects "@compuserve.com" in the hostname.
1019 If you are using IMAP, Microsoft's NTLM authentication (used by Microsoft
1020 Exchange) is supported. If you compile in the support, \fIfetchmail\fR
1021 will try to perform an NTLM authentication (instead of sending over the
1022 password en clair) whenever the server returns AUTH=NTLM in its
1023 capability response. Specify a user option value that looks like
1024 \&'user@domain': the part to the left of the @ will be passed as the
1025 username and the part to the right as the NTLM domain.
1026 .SS Secure Socket Layers (SSL) and Transport Layer Security (TLS)
1028 You can access SSL encrypted services by specifying the \-\-ssl option.
1029 You can also do this using the "ssl" user option in the .fetchmailrc
1030 file. With SSL encryption enabled, queries are initiated over a connection
1031 after negotiating an SSL session. Some services, such as POP3 and IMAP,
1032 have different well known ports defined for the SSL encrypted services.
1033 The encrypted ports will be selected automatically when SSL is enabled and
1034 no explicit port is specified.
1036 When connecting to an SSL encrypted server, the server presents a certificate
1037 to the client for validation. The certificate is checked to verify that
1038 the common name in the certificate matches the name of the server being
1039 contacted and that the effective and expiration dates in the certificate
1040 indicate that it is currently valid. If any of these checks fail, a warning
1041 message is printed, but the connection continues. The server certificate
1042 does not need to be signed by any specific Certifying Authority and may
1043 be a "self-signed" certificate.
1045 Some SSL encrypted servers may request a client side certificate. A client
1046 side public SSL certificate and private SSL key may be specified. If
1047 requested by the server, the client certificate is sent to the server for
1048 validation. Some servers may require a valid client certificate and may
1049 refuse connections if a certificate is not provided or if the certificate
1050 is not valid. Some servers may require client side certificates be signed
1051 by a recognized Certifying Authority. The format for the key files and
1052 the certificate files is that required by the underlying SSL libraries
1053 (OpenSSL in the general case).
1055 A word of care about the use of SSL: While above mentioned
1056 setup with self-signed server certificates retrieved over the wires
1057 can protect you from a passive eavesdropper it doesn't help against an
1058 active attacker. It's clearly an improvement over sending the
1059 passwords in clear but you should be aware that a man-in-the-middle
1060 attack is trivially possible (in particular with tools such as dsniff,
1061 http://monkey.org/~dugsong/dsniff/). Use of an ssh tunnel (see
1062 below for some examples) is preferable if you care seriously about the
1063 security of your mailbox.
1067 also supports authentication to the ESMTP server on the client side
1068 according to RFC 2554. You can specify a name/password pair to be
1069 used with the keywords 'esmtpname' and 'esmtppassword'; the former
1070 defaults to the username of the calling user.
1074 .B \-\-daemon <interval>
1079 in daemon mode. You must specify a numeric argument which is a
1080 polling interval in seconds.
1084 puts itself in background and runs forever, querying each specified
1085 host and then sleeping for the given polling interval.
1091 will, therefore, poll all the hosts described in your
1093 file (except those explicitly excluded with the 'skip' verb) once
1094 every fifteen minutes.
1096 It is possible to set a polling interval
1099 file by saying 'set daemon <interval>', where <interval> is an
1100 integer number of seconds. If you do this, fetchmail will always
1101 start in daemon mode unless you override it with the command-line
1102 option \-\-daemon 0 or \-d0.
1104 Only one daemon process is permitted per user; in daemon mode,
1106 makes a per-user lockfile to guarantee this.
1108 Normally, calling fetchmail with a daemon in the background sends a
1109 wake-up signal to the daemon, forcing it to poll mailservers
1110 immediately. (The wake-up signal is SIGHUP if fetchmail is running as
1111 root, SIGUSR1 otherwise.) The wake-up action also clears any 'wedged'
1112 flags indicating that connections have wedged due to failed
1113 authentication or multiple timeouts.
1117 will kill a running daemon process instead of waking it up (if there
1118 is no such process, \fIfetchmail\fP will notify you.
1119 If the \-\-quit option appears last on the command line, \fIfetchmail\fP
1120 will kill the running daemon process and then quit. Otherwise,
1121 \fIfetchmail\fP will first kill a running daemon process and then
1122 continue running with the other options.
1127 .B \-\-logfile <filename>
1128 option (keyword: set logfile) is only effective when fetchmail is
1129 detached. This option allows you to redirect status messages
1130 into a specified logfile (follow the option with the logfile name). The
1131 logfile is opened for append, so previous messages aren't deleted. This
1132 is primarily useful for debugging configurations.
1136 option (keyword: set syslog) allows you to redirect status and error
1137 messages emitted to the
1139 system daemon if available.
1140 Messages are logged with an id of \fBfetchmail\fR, the facility \fBLOG_MAIL\fR,
1141 and priorities \fBLOG_ERR\fR, \fBLOG_ALERT\fR or \fBLOG_INFO\fR.
1142 This option is intended for logging status and error messages which
1143 indicate the status of the daemon and the results while fetching mail
1145 Error messages for command line options and parsing the \fI.fetchmailrc\fR
1146 file are still written to stderr, or to the specified log file.
1149 option turns off use of
1151 assuming it's turned on in the
1156 .B \-\-logfile <file>
1163 option suppresses backgrounding and detachment of the
1164 daemon process from its control terminal. This is useful
1165 for debugging or when fetchmail runs as the child of a supervisor
1170 Note that this also causes the logfile option to be
1171 ignored (though perhaps it shouldn't).
1173 Note that while running in daemon mode polling a POP2 or IMAP2bis server,
1174 transient errors (such as DNS failures or sendmail delivery refusals)
1175 may force the fetchall option on for the duration of the next polling
1176 cycle. This is a robustness feature. It means that if a message is
1177 fetched (and thus marked seen by the mailserver) but not delivered
1178 locally due to some transient error, it will be re-fetched during the
1179 next poll cycle. (The IMAP logic doesn't delete messages until
1180 they're delivered, so this problem does not arise.)
1182 If you touch or change the
1184 file while fetchmail is running in daemon mode, this will be detected
1185 at the beginning of the next poll cycle. When a changed
1187 is detected, fetchmail rereads it and restarts from scratch (using
1188 exec(2); no state information is retained in the new instance). Note also
1189 that if you break the
1191 file's syntax, the new instance will softly and silently vanish away
1194 .SH ADMINISTRATIVE OPTIONS
1197 .B \-\-postmaster <name>
1198 option (keyword: set postmaster) specifies the last-resort username to
1199 which multidrop mail is to be forwarded if no matching local recipient
1200 can be found. It is also used as destination of undeliverable mail if
1201 the 'bouncemail' global option is off and additionally for spam-blocked
1202 mail if the 'bouncemail' global option is off and the 'spambounce'
1203 global option is on. This option defaults to the user who invoked
1205 If the invoking user is root, then the default of this option is
1206 the user 'postmaster'. Setting postmaster to the empty string causes
1207 such mail as described above to be discarded - this however is usually a
1209 See also the description of the 'FETCHMAILUSER' environment variable in
1210 the ENVIRONMENT section below.
1214 behaves like the "set no bouncemail" global option, which see.
1218 option (keyword: set invisible) tries to make fetchmail invisible.
1219 Normally, fetchmail behaves like any other MTA would -- it generates a
1220 Received header into each message describing its place in the chain of
1221 transmission, and tells the MTA it forwards to that the mail came from
1222 the machine fetchmail itself is running on. If the invisible option
1223 is on, the Received header is suppressed and fetchmail tries to spoof
1224 the MTA it forwards to into thinking it came directly from the
1229 option (keyword: set showdots) forces fetchmail to show progress dots
1230 even if the current tty is not stdout (for example logfiles).
1231 Fetchmail shows the dots by default when run in nodetach mode or when
1232 daemon mode is not enabled.
1236 option, you can ask fetchmail to add information to the Received
1237 header on the form "polling {label} account {user}", where {label} is
1238 the account label (from the specified rcfile, normally ~/.fetchmailrc)
1239 and {user} is the username which is used to log on to the mail
1240 server. This header can be used to make filtering email where no
1241 useful header information is available and you want mail from
1242 different accounts sorted into different mailboxes (this could, for
1243 example, occur if you have an account on the same server running a
1244 mailing list, and are subscribed to the list using that account). The
1245 default is not adding any such header. In
1247 this is called 'tracepolls'.
1249 .SH RETRIEVAL FAILURE MODES
1250 The protocols \fIfetchmail\fR uses to talk to mailservers are next to
1251 bulletproof. In normal operation forwarding to port 25, no message is
1252 ever deleted (or even marked for deletion) on the host until the SMTP
1253 listener on the client side has acknowledged to \fIfetchmail\fR that
1254 the message has been either accepted for delivery or rejected due to a
1257 When forwarding to an MDA, however, there is more possibility
1258 of error. Some MDAs are 'safe' and reliably return a nonzero status
1259 on any delivery error, even one due to temporary resource limits.
1262 program is like this; so are most programs designed as mail transport
1265 including the sendmail wrapper of Postfix and
1267 These programs give back a reliable positive acknowledgement and
1268 can be used with the mda option with no risk of mail loss. Unsafe
1269 MDAs, though, may return 0 even on delivery failure. If this
1270 happens, you will lose mail.
1272 The normal mode of \fIfetchmail\fR is to try to download only 'new'
1273 messages, leaving untouched (and undeleted) messages you have already
1274 read directly on the server (or fetched with a previous \fIfetchmail
1275 --keep\fR). But you may find that messages you've already read on the
1276 server are being fetched (and deleted) even when you don't specify
1277 --all. There are several reasons this can happen.
1279 One could be that you're using POP2. The POP2 protocol includes no
1280 representation of 'new' or 'old' state in messages, so \fIfetchmail\fR
1281 must treat all messages as new all the time. But POP2 is obsolete, so
1284 A potential POP3 problem might be servers that insert messages
1285 in the middle of mailboxes (some VMS implementations of mail are
1286 rumored to do this). The \fIfetchmail\fR code assumes that new
1287 messages are appended to the end of the mailbox; when this is not true
1288 it may treat some old messages as new and vice versa. Using UIDL whilst
1289 setting fastuidl 0 might fix this, otherwise, consider switching to IMAP.
1291 Yet another POP3 problem is that if they can't make tempfiles in the
1292 user's home directory, some POP3 servers will hand back an
1293 undocumented response that causes fetchmail to spuriously report "No
1296 The IMAP code uses the presence or absence of the server flag \eSeen
1297 to decide whether or not a message is new. This isn't the right thing
1298 to do, fetchmail should check the UIDVALIDITY and use UID, but it
1299 doesn't do that yet. Under Unix, it counts on your IMAP server to notice
1300 the BSD-style Status flags set by mail user agents and set the \eSeen
1301 flag from them when appropriate. All Unix IMAP servers we know of do
1302 this, though it's not specified by the IMAP RFCs. If you ever trip over
1303 a server that doesn't, the symptom will be that messages you have
1304 already read on your host will look new to the server. In this
1305 (unlikely) case, only messages you fetched with \fIfetchmail \-\-keep\fR
1306 will be both undeleted and marked old.
1308 In ETRN and ODMR modes, \fIfetchmail\fR does not actually retrieve messages;
1309 instead, it asks the server's SMTP listener to start a queue flush
1310 to the client via SMTP. Therefore it sends only undelivered messages.
1313 Many SMTP listeners allow administrators to set up 'spam filters' that
1314 block unsolicited email from specified domains. A MAIL FROM or DATA line that
1315 triggers this feature will elicit an SMTP response which
1316 (unfortunately) varies according to the listener.
1320 return an error code of 571.
1322 According to RFC2821, the correct thing to return in this situation is
1323 550 "Requested action not taken: mailbox unavailable" (the draft adds
1324 "[E.g., mailbox not found, no access, or command rejected for policy
1327 Older versions of the
1329 MTA return 501 "Syntax error in parameters or arguments".
1333 MTA runs 554 as an antispam response.
1336 may reject code with a 500 response (followed by an enhanced status
1337 code that contains more information).
1341 treats as antispam responses and discards
1342 the message can be set with the 'antispam' option. This is one of the
1344 three circumstance under which fetchmail ever discards mail (the others
1345 are the 552 and 553 errors described below, and the suppression of
1346 multidropped messages with a message-ID already seen).
1350 is fetching from an IMAP server, the antispam response will be detected and
1351 the message rejected immediately after the headers have been fetched,
1352 without reading the message body. Thus, you won't pay for downloading
1353 spam message bodies.
1355 By default, the list of antispam responses is empty.
1357 If the \fIspambounce\fR global option is on, mail that is spam-blocked
1358 triggers an RFC1892/RFC1894 bounce message informing the originator that
1359 we do not accept mail from it. See also BUGS.
1361 .SH SMTP/ESMTP ERROR HANDLING
1362 Besides the spam-blocking described above, fetchmail takes special
1363 actions on the following SMTP/ESMTP error responses
1365 452 (insufficient system storage)
1366 Leave the message in the server mailbox for later retrieval.
1368 552 (message exceeds fixed maximum message size)
1369 Delete the message from the server. Send bounce-mail to the
1372 553 (invalid sending domain)
1373 Delete the message from the server. Don't even try to send
1374 bounce-mail to the originator.
1376 Other errors trigger bounce mail back to the originator. See also BUGS.
1378 .SH THE RUN CONTROL FILE
1379 The preferred way to set up fetchmail is to write a
1380 \&\fI.fetchmailrc\fR file in your home directory (you may do this
1381 directly, with a text editor, or indirectly via \fIfetchmailconf\fR).
1382 When there is a conflict between the command-line arguments and the
1383 arguments in this file, the command-line arguments take precedence.
1385 To protect the security of your passwords,
1386 your \fI~/.fetchmailrc\fR may not normally have more than 0600 (u=rw,g=,o=) permissions;
1388 will complain and exit otherwise (this check is suppressed when
1391 You may read the \fI.fetchmailrc\fR file as a list of commands to
1394 is called with no arguments.
1395 .SS Run Control Syntax
1397 Comments begin with a '#' and extend through the end of the line.
1398 Otherwise the file consists of a series of server entries or global
1399 option statements in a free-format, token-oriented syntax.
1401 There are four kinds of tokens: grammar keywords, numbers
1402 (i.e. decimal digit sequences), unquoted strings, and quoted strings.
1403 A quoted string is bounded by double quotes and may contain
1404 whitespace (and quoted digits are treated as a string). Note that
1405 quoted strings will also contain line feed characters if they run across
1406 two or more lines, unless you use a backslash to join lines (see below).
1407 An unquoted string is any whitespace-delimited token that is neither
1408 numeric, string quoted nor contains the special characters ',', ';',
1411 Any amount of whitespace separates tokens in server entries, but is
1412 otherwise ignored. You may use backslash escape sequences (\en for LF,
1413 \&\et for HT, \eb for BS, \er for CR, \e\fInnn\fP for decimal (where
1414 nnn cannot start with a 0), \e0\fIooo\fP for octal, and \ex\fIhh\fP for
1415 hex) to embed non-printable characters or string delimiters in strings.
1416 In quoted strings, a backslash at the very end of a line will cause the
1417 backslash itself and the line feed (LF or NL, new line) character to be
1418 ignored, so that you can wrap long strings. Without the backslash at the
1419 line end, the line feed character would become part of the string.
1422 while these resemble C-style escape sequences, they are not the same.
1423 fetchmail only supports these eight styles. C supports more escape
1424 sequences that consist of backslash (\e) and a single character, but
1425 does not support decimal codes and does not require the leading 0 in
1426 octal notation. Example: fetchmail interprets \e233 the same as \exE9
1427 (Latin small letter e with acute), where C would interpret \e233 as
1428 octal 0233 = \ex9B (CSI, control sequence introducer).
1430 Each server entry consists of one of the keywords 'poll' or 'skip',
1431 followed by a server name, followed by server options, followed by any
1432 number of user descriptions. Note: the most common cause of syntax
1433 errors is mixing up user and server options.
1435 For backward compatibility, the word 'server' is a synonym for 'poll'.
1437 You can use the noise keywords 'and', 'with',
1438 \&'has', 'wants', and 'options' anywhere in an entry to make
1439 it resemble English. They're ignored, but but can make entries much
1440 easier to read at a glance. The punctuation characters ':', ';' and
1441 \&',' are also ignored.
1444 The 'poll' verb tells fetchmail to query this host when it is run with
1445 no arguments. The 'skip' verb tells
1447 not to poll this host unless it is explicitly named on the command
1448 line. (The 'skip' verb allows you to experiment with test entries
1449 safely, or easily disable entries for hosts that are temporarily down.)
1451 .SS Keyword/Option Summary
1452 Here are the legal options. Keyword suffixes enclosed in
1453 square brackets are optional. Those corresponding to short command-line
1454 options are followed by '\-' and the appropriate option letter. If
1455 option is only relevant to a single mode of operation, it is noted as
1456 \&'s' or 'm' for singledrop- or multidrop-mode, respectively.
1458 Here are the legal global options:
1462 Keyword Opt Mode Function
1464 set daemon \-d \& T{
1465 Set a background poll interval in seconds.
1467 set postmaster \& \& T{
1468 Give the name of the last-resort mail recipient (default: user running
1469 fetchmail, "postmaster" if run by the root user)
1471 set bouncemail \& \& T{
1472 Direct error mail to the sender (default)
1474 set no bouncemail \& \& T{
1475 Direct error mail to the local postmaster (as per the 'postmaster'
1476 global option above).
1478 set no spambounce \& \& T{
1479 Do not bounce spam-blocked mail (default).
1481 set spambounce \& \& T{
1482 Bounce blocked spam-blocked mail (as per the 'antispam' user option)
1483 back to the destination as indicated by the 'bouncemail' global option.
1484 Warning: Do not use this to bounce spam back to the sender - most spam
1485 is sent with false sender address and thus this option hurts innocent
1488 set logfile \-L \& T{
1489 Name of a file to append error and status messages to.
1491 set idfile \-i \& T{
1492 Name of the file to store UID lists in.
1495 Do error logging through syslog(3).
1497 set no syslog \& \& T{
1498 Turn off error logging through syslog(3). (default)
1500 set properties \& \& T{
1501 String value that is ignored by fetchmail (may be used by extension
1506 Here are the legal server options:
1510 Keyword Opt Mode Function
1513 Specify DNS name of mailserver, overriding poll name
1515 proto[col] \-p \& T{
1516 Specify protocol (case insensitive):
1517 POP2, POP3, IMAP, APOP, KPOP
1519 local[domains] \& m T{
1520 Specify domain(s) to be regarded as local
1523 Specify TCP/IP service port (obsolete, use 'service' instead).
1526 Specify service name (a numeric value is also allowed and
1527 considered a TCP/IP port number).
1529 auth[enticate] \& \& T{
1530 Set authentication type (default 'any')
1533 Server inactivity timeout in seconds (default 300)
1536 Specify envelope-address header name
1539 Disable looking for envelope address
1542 Qmail virtual domain prefix to remove from user name
1545 Specify alternate DNS names of mailserver
1548 specify IP interface(s) that must be up for server poll to take place
1551 Specify IP address to monitor for activity
1554 Specify command through which to make server connections.
1557 Specify command through which to make listener connections.
1560 Enable DNS lookup for multidrop (default)
1563 Disable DNS lookup for multidrop
1566 Do comparison by IP address for multidrop
1568 no checkalias \& m T{
1569 Do comparison by name for multidrop (default)
1572 Force POP3 to use client-side UIDLs (recommended)
1575 Turn off POP3 use of client-side UIDLs (default)
1578 Only check this site every N poll cycles; N is a numeric argument.
1581 Add poll tracing information to the Received header
1584 Set Kerberos principal (only useful with imap and kerberos)
1587 Set name for RFC2554 authentication to the ESMTP server.
1589 esmtppassword \& \& T{
1590 Set password for RFC2554 authentication to the ESMTP server.
1594 Here are the legal user options:
1598 Keyword Opt Mode Function
1600 user[name] \-u \& T{
1601 Set remote user name
1602 (local user name if name followed by 'here')
1605 Connect local and remote user names
1608 Connect local and remote user names
1611 Specify remote account password
1614 Connect to server over the specified base protocol using SSL encryption
1617 Specify file for client side public SSL certificate
1620 Specify file for client side private SSL key
1623 Force ssl protocol for connection
1626 Specify remote folder to query
1629 Specify smtp host(s) to forward to
1631 fetchdomains \& m T{
1632 Specify domains for which mail should be fetched
1634 smtpaddress \-D \& T{
1635 Specify the domain to be put in RCPT TO lines
1638 Specify the user and domain to be put in RCPT TO lines
1641 Specify what SMTP returns are interpreted as spam-policy blocks
1644 Specify MDA for local delivery
1647 Specify BSMTP batch file to append to
1650 Command to be executed before each connection
1652 postconnect \& \& T{
1653 Command to be executed after each connection
1656 Don't delete seen messages from server
1659 Flush all seen messages before querying (DANGEROUS)
1662 Flush all oversized messages before querying
1665 Fetch all messages whether seen or not
1668 Rewrite destination addresses for reply (default)
1671 Strip carriage returns from ends of lines
1674 Force carriage returns at ends of lines
1677 Force BODY=8BITMIME to ESMTP listener
1680 Strip Status and X-Mozilla-Status lines out of incoming mail
1682 dropdelivered \& \& T{
1683 Strip Delivered-To lines out of incoming mail
1686 Convert quoted-printable to 8-bit in MIME messages
1689 Idle waiting for new messages after each poll (IMAP only)
1692 Delete seen messages from server (default)
1695 Don't flush all seen messages before querying (default)
1697 no fetchall \& \& T{
1698 Retrieve only new messages (default)
1701 Don't rewrite headers
1704 Don't strip carriage returns (default)
1707 Don't force carriage returns at EOL (default)
1709 no pass8bits \& \& T{
1710 Don't force BODY=8BITMIME to ESMTP listener (default)
1712 no dropstatus \& \& T{
1713 Don't drop Status headers (default)
1715 no dropdelivered \& \& T{
1716 Don't drop Delivered\-To headers (default)
1718 no mimedecode \& \& T{
1719 Don't convert quoted-printable to 8-bit in MIME messages (default)
1722 Don't idle waiting for new messages after each poll (IMAP only)
1725 Set message size limit
1728 Set message size warning interval
1730 batchlimit \-b \& T{
1731 Max # messages to forward in single connect
1733 fetchlimit \-B \& T{
1734 Max # messages to fetch in single connect
1736 fetchsizelimit \& \& T{
1737 Max # message sizes to fetch in single transaction
1740 Use binary search for first unseen message (POP3 only)
1743 Perform an expunge on every #th message (IMAP and POP3 only)
1746 String value is ignored by fetchmail (may be used by extension scripts)
1750 Remember that all user options must \fIfollow\fR all server options.
1752 In the .fetchmailrc file, the 'envelope' string argument may be
1753 preceded by a whitespace-separated number. This number, if specified,
1754 is the number of such headers to skip over (that is, an argument of 1
1755 selects the second header of the given type). This is sometime useful
1756 for ignoring bogus envelope headers created by an ISP's local delivery
1757 agent or internal forwards (through mail inspection systems, for
1759 .SS Keywords Not Corresponding To Option Switches
1761 The 'folder' and 'smtphost' options (unlike their command-line
1762 equivalents) can take a space- or comma-separated list of names
1765 All options correspond to the obvious command-line arguments, except
1766 the following: 'via', 'interval', 'aka', 'is', 'to', 'dns'/'no dns',
1767 \&'checkalias'/'no checkalias', 'password', 'preconnect', 'postconnect',
1768 \&'localdomains', 'stripcr'/'no stripcr', 'forcecr'/'no forcecr',
1769 \&'pass8bits'/'no pass8bits' 'dropstatus/no dropstatus',
1770 \&'dropdelivered/no dropdelivered', 'mimedecode/no mimedecode', 'no idle',
1773 The 'via' option is for if you want to have more
1774 than one configuration pointing at the same site. If it is present,
1775 the string argument will be taken as the actual DNS name of the
1776 mailserver host to query.
1777 This will override the argument of poll, which can then simply be a
1778 distinct label for the configuration (e.g. what you would give on the
1779 command line to explicitly query this host).
1781 The 'interval' option (which takes a numeric argument) allows you to poll a
1782 server less frequently than the basic poll interval. If you say
1783 \&'interval N' the server this option is attached to will only be
1784 queried every N poll intervals.
1786 The 'is' or 'to' keywords associate the following local (client)
1787 name(s) (or server-name to client-name mappings separated by =) with
1788 the mailserver user name in the entry. If an is/to list has '*' as
1789 its last name, unrecognized names are simply passed through.
1791 A single local name can be used to support redirecting your mail when
1792 your username on the client machine is different from your name on the
1793 mailserver. When there is only a single local name, mail is forwarded
1794 to that local username regardless of the message's Received, To, Cc,
1795 and Bcc headers. In this case
1797 never does DNS lookups.
1799 When there is more than one local name (or name mapping) the
1800 \fIfetchmail\fR code does look at the Received, To, Cc, and Bcc
1801 headers of retrieved mail (this is 'multidrop mode'). It looks for
1802 addresses with hostname parts that match your poll name or your 'via',
1803 \&'aka' or 'localdomains' options, and usually also for hostname parts
1804 which DNS tells it are aliases of the mailserver. See the discussion
1805 of 'dns', 'checkalias', 'localdomains', and 'aka' for details on how
1806 matching addresses are handled.
1808 If \fIfetchmail\fR cannot match any mailserver usernames or
1809 localdomain addresses, the mail will be bounced.
1810 Normally it will be bounced to the sender, but if the 'bouncemail'
1811 global option is off, the mail will go to the local postmaster instead.
1812 (see the 'postmaster' global option). See also BUGS.
1814 The 'dns' option (normally on) controls the way addresses from
1815 multidrop mailboxes are checked. On, it enables logic to check each
1816 host address that does not match an 'aka' or 'localdomains' declaration
1817 by looking it up with DNS. When a mailserver username is recognized
1818 attached to a matching hostname part, its local mapping is added to
1819 the list of local recipients.
1821 The 'checkalias' option (normally off) extends the lookups performed
1822 by the 'dns' keyword in multidrop mode, providing a way to cope with
1823 remote MTAs that identify themselves using their canonical name, while
1824 they're polled using an alias.
1825 When such a server is polled, checks to extract the envelope address
1828 reverts to delivery using the To/Cc/Bcc headers (See below
1829 \&'Header vs. Envelope addresses').
1830 Specifying this option instructs
1832 to retrieve all the IP addresses associated with both the poll name
1833 and the name used by the remote MTA and to do a comparison of the IP
1834 addresses. This comes in handy in situations where the remote server
1835 undergoes frequent canonical name changes, that would otherwise
1836 require modifications to the rcfile. 'checkalias' has no effect if
1837 \&'no dns' is specified in the rcfile.
1839 The 'aka' option is for use with multidrop mailboxes. It allows you
1840 to pre-declare a list of DNS aliases for a server. This is an
1841 optimization hack that allows you to trade space for speed. When
1843 while processing a multidrop mailbox, grovels through message headers
1844 looking for names of the mailserver, pre-declaring common ones can
1845 save it from having to do DNS lookups. Note: the names you give
1846 as arguments to 'aka' are matched as suffixes -- if you specify
1847 (say) 'aka netaxs.com', this will match not just a hostname
1848 netaxs.com, but any hostname that ends with '.netaxs.com'; such as
1849 (say) pop3.netaxs.com and mail.netaxs.com.
1851 The 'localdomains' option allows you to declare a list of domains
1852 which fetchmail should consider local. When fetchmail is parsing
1853 address lines in multidrop modes, and a trailing segment of a host
1854 name matches a declared local domain, that address is passed through
1855 to the listener or MDA unaltered (local-name mappings are \fInot\fR
1858 If you are using 'localdomains', you may also need to specify 'no
1859 envelope', which disables \fIfetchmail\fR's normal attempt to deduce
1860 an envelope address from the Received line or X-Envelope-To header or
1861 whatever header has been previously set by 'envelope'. If you set 'no
1862 envelope' in the defaults entry it is possible to undo that in
1863 individual entries by using 'envelope <string>'. As a special case,
1864 \&'envelope "Received"' restores the default parsing of
1867 The \fBpassword\fR option requires a string argument, which is the password
1868 to be used with the entry's server.
1870 The 'preconnect' keyword allows you to specify a shell command to be
1871 executed just before each time
1873 establishes a mailserver connection. This may be useful if you are
1874 attempting to set up secure POP connections with the aid of
1876 If the command returns a nonzero status, the poll of that mailserver
1879 Similarly, the 'postconnect' keyword similarly allows you to specify a
1880 shell command to be executed just after each time a mailserver
1881 connection is taken down.
1883 The 'forcecr' option controls whether lines terminated by LF only are
1884 given CRLF termination before forwarding. Strictly speaking RFC821
1885 requires this, but few MTAs enforce the requirement it so this option
1886 is normally off (only one such MTA, qmail, is in significant use at
1889 The 'stripcr' option controls whether carriage returns are stripped
1890 out of retrieved mail before it is forwarded. It is normally not
1891 necessary to set this, because it defaults to 'on' (CR stripping
1892 enabled) when there is an MDA declared but 'off' (CR stripping
1893 disabled) when forwarding is via SMTP. If 'stripcr' and 'forcecr' are
1894 both on, 'stripcr' will override.
1896 The 'pass8bits' option exists to cope with Microsoft mail programs that
1897 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
1898 this option off (the default) and such a header present,
1900 declares BODY=7BIT to an ESMTP-capable listener; this causes problems for
1901 messages actually using 8-bit ISO or KOI-8 character sets, which will
1902 be garbled by having the high bits of all characters stripped. If
1903 \&'pass8bits' is on,
1905 is forced to declare BODY=8BITMIME to any ESMTP-capable listener. If
1906 the listener is 8-bit-clean (as all the major ones now are) the right
1907 thing will probably result.
1909 The 'dropstatus' option controls whether nonempty Status and
1910 X-Mozilla-Status lines are retained in fetched mail (the default) or
1911 discarded. Retaining them allows your MUA to see what messages (if
1912 any) were marked seen on the server. On the other hand, it can
1913 confuse some new-mail notifiers, which assume that anything with a
1914 Status line in it has been seen. (Note: the empty Status lines
1915 inserted by some buggy POP servers are unconditionally discarded.)
1917 The 'dropdelivered' option controls whether Delivered\-To headers will
1918 be kept in fetched mail (the default) or discarded. These headers are
1919 added by Qmail and Postfix mailservers in order to avoid mail loops but
1920 may get in your way if you try to "mirror" a mailserver within the same
1921 domain. Use with caution.
1923 The 'mimedecode' option controls whether MIME messages using the
1924 quoted-printable encoding are automatically converted into pure 8-bit
1925 data. If you are delivering mail to an ESMTP-capable, 8-bit-clean
1926 listener (that includes all of the major MTAs like sendmail), then
1927 this will automatically convert quoted-printable message headers and
1928 data into 8-bit data, making it easier to understand when reading
1929 mail. If your e-mail programs know how to deal with MIME messages,
1930 then this option is not needed. The mimedecode option is off by
1931 default, because doing RFC2047 conversion on headers throws away
1932 character-set information and can lead to bad results if the encoding
1933 of the headers differs from the body encoding.
1935 The 'idle' option is intended to be used with IMAP servers supporting
1936 the RFC2177 IDLE command extension, but does not strictly require it.
1937 If it is enabled, and fetchmail detects that IDLE is supported, an
1938 IDLE will be issued at the end of each poll. This will tell the IMAP
1939 server to hold the connection open and notify the client when new mail
1940 is available. If IDLE is not supported, fetchmail will simulate it by
1941 periodically issuing NOOP. If you need to poll a link frequently, IDLE
1942 can save bandwidth by eliminating TCP/IP connects and LOGIN/LOGOUT
1943 sequences. On the other hand, an IDLE connection will eat almost all
1944 of your fetchmail's time, because it will never drop the connection
1945 and allow other polls to occur unless the server times out the IDLE.
1946 It also doesn't work with multiple folders; only the first folder will
1950 The 'properties' option is an extension mechanism. It takes a string
1951 argument, which is ignored by fetchmail itself. The string argument may be
1952 used to store configuration information for scripts which require it.
1953 In particular, the output of '\-\-configdump' option will make properties
1954 associated with a user entry readily available to a Python script.
1956 .SS Miscellaneous Run Control Options
1957 The words 'here' and 'there' have useful English-like
1958 significance. Normally 'user eric is esr' would mean that
1959 mail for the remote user 'eric' is to be delivered to 'esr',
1960 but you can make this clearer by saying 'user eric there is esr here',
1961 or reverse it by saying 'user esr here is eric there'
1963 Legal protocol identifiers for use with the 'protocol' keyword are:
1966 auto (or AUTO) (legacy, to be removed from future release)
1967 pop2 (or POP2) (legacy, to be removed from future release)
1976 Legal authentication types are 'any', 'password', 'kerberos',
1977 \&'kerberos_v4', 'kerberos_v5' and 'gssapi', 'cram\-md5', 'otp', 'msn'
1978 (only for POP3), 'ntlm', 'ssh'. The 'password' type specifies
1979 authentication by normal transmission of a password (the password may be
1980 plain text or subject to protocol-specific encryption as in APOP);
1981 \&'kerberos' tells \fIfetchmail\fR to try to get a Kerberos ticket at the
1982 start of each query instead, and send an arbitrary string as the
1983 password; and 'gssapi' tells fetchmail to use GSSAPI authentication.
1984 See the description of the 'auth' keyword for more.
1986 Specifying 'kpop' sets POP3 protocol over port 1109 with Kerberos V4
1987 authentication. These defaults may be overridden by later options.
1989 There are some global option statements: 'set logfile'
1990 followed by a string sets the same global specified by \-\-logfile. A
1991 command-line \-\-logfile option will override this. Note that \-\-logfile is
1992 only effective if fetchmail detaches itself from the terminal. Also,
1993 \&'set daemon' sets the poll interval as \-\-daemon does. This can be
1994 overridden by a command-line \-\-daemon option; in particular \-\-daemon\~0
1995 can be used to force foreground operation. The 'set postmaster'
1996 statement sets the address to which multidrop mail defaults if there are
1997 no local matches. Finally, 'set syslog' sends log messages to
2000 .SH DEBUGGING FETCHMAIL
2001 .SS Fetchmail crashing
2002 There are various ways in that fetchmail may "crash", i. e. stop
2003 operation suddenly and unexpectedly. A "crash" usually refers to an
2004 error condition that the software did not handle by itself. A well-known
2005 failure mode is the "segmentation fault" or "signal 11" or "SIGSEGV" or
2006 just "segfault" for short. These can be caused by hardware or by software
2007 problems. Software-induced segfaults can usually be reproduced easily
2008 and in the same place, whereas hardware-induced segfaults can go away if
2009 the computer is rebooted, or powered off for a few hours, and can happen
2010 in random locations even if you use the software the same way.
2012 For solving hardware-induced segfaults, find the faulty component and repair or
2013 replace it. <http://www.bitwizard.nl/sig11/> may help you with details.
2015 For solving software-induced segfaults, the developers may need a "stack
2018 .SS Enabling fetchmail core dumps
2019 By default, fetchmail suppresses core dumps as these might contain
2020 passwords and other sensitive information. For debugging fetchmail
2021 crashes, obtaining a "stack backtrace" from a core dump is often the
2022 quickest way to solve the problem, and when posting your problem on a
2023 mailing list, the developers may ask you for a "backtrace".
2025 1. To get useful backtraces, fetchmail needs to be installed without
2026 getting stripped of its compilation symbols. Unfortunately, most
2027 binary packages that are installed are stripped, and core files from
2028 symbol-stripped programs are worthless. So you may need to recompile
2029 fetchmail. On many systems, you can type
2032 file `which fetchmail`
2035 to find out if fetchmail was symbol-stripped or not. If yours was
2036 unstripped, fine, proceed, if it was stripped, you need to recompile the
2037 source code first. You do not usually need to install fetchmail in order
2040 2. The shell environment that starts fetchmail needs to enable core
2041 dumps. The key is the "maximum core (file) size" that can usually be
2042 configured with a tool named "limit" or "ulimit". See the documentation
2043 for your shell for details. In the popular bash shell, "ulimit \-Sc
2044 unlimited" will allow the core dump.
2046 3. You need to tell fetchmail, too, to allow core dumps. To do
2047 this, run fetchmail with the \fB\-d0 \-v\fP options. It is often easier
2048 to also add \fB\-\-nosyslog \-N\fR as well.
2050 Finally, you need to reproduce the crash. You can just start fetchmail
2051 from the directory where you compiled it by typing \fB./fetchmail\fR,
2052 so the complete command line will start with \fB./fetchmail \-Nvd0
2053 \&\-\-nosyslog\fR and perhaps list your other options.
2055 After the crash, run your debugger to obtain the core dump. The
2056 debugger will often be GNU GDB, you can then type (adjust paths as
2057 necessary) \fBgdb ./fetchmail fetchmail.core\fR and then, after GDB
2058 has started up and read all its files, type \fBbacktrace full\fR, save
2059 the output (copy & paste will do, the backtrace will be read by a human)
2060 and then type \fBquit\fR to leave gdb.
2062 on some systems, the core
2063 files have different names, they might contain a number instead of the
2064 program name, or number and name, but it will usually have "core" as
2067 .SH INTERACTION WITH RFC 822
2068 When trying to determine the originating address of a message,
2069 fetchmail looks through headers in the following order:
2073 Resent-Sender: (ignored if it doesn't contain an @ or !)
2074 Sender: (ignored if it doesn't contain an @ or !)
2081 The originating address is used for logging, and to set the MAIL FROM
2082 address when forwarding to SMTP. This order is intended to cope
2083 gracefully with receiving mailing list messages in multidrop mode. The
2084 intent is that if a local address doesn't exist, the bounce message
2085 won't be returned blindly to the author or to the list itself, but
2086 rather to the list manager (which is less annoying).
2088 In multidrop mode, destination headers are processed as follows:
2089 First, fetchmail looks for the Received: header (or whichever one is
2090 specified by the 'envelope' option) to determine the local
2091 recipient address. If the mail is addressed to more than one recipient,
2092 the Received line won't contain any information regarding recipient addresses.
2094 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
2095 lines. If they exist, they should contain the final recipients and
2096 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent\-*
2097 lines don't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
2098 looked for. (The presence of a Resent\-To: is taken to imply that the
2099 person referred by the To: address has already received the original
2102 .SH CONFIGURATION EXAMPLES
2103 Note that although there are password declarations in a good many
2104 of the examples below, this is mainly for illustrative purposes.
2105 We recommend stashing account/password pairs in your $HOME/.netrc
2106 file, where they can be used not just by fetchmail but by ftp(1) and
2112 poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD
2118 poll pop.provider.net protocol pop3 username "jsmith" password "secret1"
2121 Or, using some abbreviations:
2124 poll pop.provider.net proto pop3 user "jsmith" password "secret1"
2127 Multiple servers may be listed:
2130 poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
2131 poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"
2134 Here's a version of those two with more whitespace and some noise words:
2137 poll pop.provider.net proto pop3
2138 user "jsmith", with password secret1, is "jsmith" here;
2139 poll other.provider.net proto pop2:
2140 user "John.Smith", with password "My^Hat", is "John.Smith" here;
2143 This version is much easier to read and doesn't cost significantly
2144 more (parsing is done only once, at startup time).
2147 If you need to include whitespace in a parameter string, enclose the
2148 string in double quotes. Thus:
2151 poll mail.provider.net with proto pop3:
2152 user "jsmith" there has password "u can't krak this"
2153 is jws here and wants mda "/bin/mail"
2156 You may have an initial server description headed by the keyword
2157 \&'defaults' instead of 'poll' followed by a name. Such a record
2158 is interpreted as defaults for all queries to use. It may be overwritten
2159 by individual server descriptions. So, you could write:
2164 poll pop.provider.net
2166 poll mail.provider.net
2167 user "jjsmith" there has password "secret2"
2170 It's possible to specify more than one user per server (this is only
2171 likely to be useful when running fetchmail in daemon mode as root).
2172 The 'user' keyword leads off a user description, and every user specification
2173 in a multi-user entry must include it. Here's an example:
2176 poll pop.provider.net proto pop3 port 3111
2177 user "jsmith" with pass "secret1" is "smith" here
2178 user jones with pass "secret2" is "jjones" here keep
2181 This associates the local username 'smith' with the pop.provider.net
2182 username 'jsmith' and the local username 'jjones' with the
2183 pop.provider.net username 'jones'. Mail for 'jones' is kept on the
2184 server after download.
2186 Here's what a simple retrieval configuration for a multi-drop mailbox
2190 poll pop.provider.net:
2191 user maildrop with pass secret1 to golux 'hurkle'='happy' snark here
2194 This says that the mailbox of account 'maildrop' on the server is a
2195 multi-drop box, and that messages in it should be parsed for the
2196 server user names 'golux', 'hurkle', and 'snark'. It further
2197 specifies that 'golux' and 'snark' have the same name on the
2198 client as on the server, but mail for server user 'hurkle' should be
2199 delivered to client user 'happy'.
2201 Here's an example of another kind of multidrop connection:
2204 poll pop.provider.net localdomains loonytoons.org toons.org:
2205 user maildrop with pass secret1 to * here
2208 This also says that the mailbox of account 'maildrop' on the server is
2209 a multi-drop box. It tells fetchmail that any address in the
2210 loonytoons.org or toons.org domains (including sub-domain addresses like
2211 \&'joe@daffy.loonytoons.org') should be passed through to the local SMTP
2212 listener without modification. Be careful of mail loops if you do this!
2214 Here's an example configuration using ssh and the plugin option. The
2215 queries are made directly on the stdin and stdout of imapd via ssh.
2216 Note that in this setup, IMAP authentication can be skipped.
2219 poll mailhost.net with proto imap:
2220 plugin "ssh %h /usr/sbin/imapd" auth ssh;
2221 user esr is esr here
2224 .SH THE USE AND ABUSE OF MULTIDROP MAILBOXES
2225 Use the multiple-local-recipients feature with caution -- it can bite.
2226 All multidrop features are ineffective in ETRN and ODMR modes.
2228 Also, note that in multidrop mode duplicate mails are suppressed. A
2229 piece of mail is considered duplicate if it has the same message-ID as
2230 the message immediately preceding and more than one addressee. Such
2231 runs of messages may be generated when copies of a message addressed
2232 to multiple users are delivered to a multidrop box.
2234 .SS Header vs. Envelope addresses
2235 The fundamental problem is that by having your mailserver toss several
2236 peoples' mail in a single maildrop box, you may have thrown away
2237 potentially vital information about who each piece of mail was
2238 actually addressed to (the 'envelope address', as opposed to the
2239 header addresses in the RFC822 To/Cc headers - the Bcc is not available
2240 at the receiving end). This 'envelope address' is the address you need
2241 in order to reroute mail properly.
2245 can deduce the envelope address. If the mailserver MTA is
2247 and the item of mail had just one recipient, the MTA will have written
2248 a 'by/for' clause that gives the envelope addressee into its Received
2249 header. But this doesn't work reliably for other MTAs, nor if there is
2250 more than one recipient. By default, \fIfetchmail\fR looks for
2251 envelope addresses in these lines; you can restore this default with
2252 \&\-E "Received" or 'envelope Received'.
2254 .B As a better alternative,
2255 some SMTP listeners and/or mail servers insert a header
2256 in each message containing a copy of the envelope addresses. This
2257 header (when it exists) is often 'X\-Original\-To', 'Delivered\-To' or
2258 \&'X\-Envelope\-To'. Fetchmail's assumption about this can be changed with
2259 the \-E or 'envelope' option. Note that writing an envelope header of
2260 this kind exposes the names of recipients (including blind-copy
2261 recipients) to all receivers of the messages, so the upstream must store
2262 one copy of the message per recipient to avoid becoming a privacy problem.
2264 Postfix, since version 2.0, writes an X\-Original\-To: header which
2265 contains a copy of the envelope as it was received.
2267 Qmail and Postfix generally write a 'Delivered\-To' header upon
2268 delivering the message to the mail spool and use it to avoid mail loops.
2269 Qmail virtual domains however will prefix the user name with a string
2270 that normally matches the user's domain. To remove this prefix you can
2271 use the \-Q or 'qvirtual' option.
2273 Sometimes, unfortunately, neither of these methods works. That is the
2274 point when you should contact your ISP and ask them to provide such an
2275 envelope header, and you should not use multidrop in this situation.
2276 When they all fail, fetchmail must fall back on the contents of To/Cc
2277 headers (Bcc headers are not available - see below) to try to determine
2278 recipient addressees -- and these are unreliable.
2279 In particular, mailing-list software often ships mail with only
2280 the list broadcast address in the To header.
2282 .B Note that a future version of fetchmail may remove To/Cc parsing!
2286 cannot deduce a recipient address that is local, and the intended
2287 recipient address was anyone other than fetchmail's invoking user,
2288 .B mail will get lost.
2289 This is what makes the multidrop feature risky without proper envelope
2292 A related problem is that when you blind-copy a mail message, the Bcc
2293 information is carried \fIonly\fR as envelope address (it's removed from
2294 the headers by the sending mail server, so fetchmail can see it only if
2295 there is an X-\Envelope\-To header). Thus, blind-copying to someone who
2296 gets mail over a fetchmail multidrop link will fail unless the the
2297 mailserver host routinely writes X\-Envelope\-To or an equivalent header
2298 into messages in your maildrop.
2300 \fBIn conclusion, mailing lists and Bcc'd mail can only work if the
2301 server you're fetching from (1) stores one copy of the message per
2302 recipient in \fIyour\fP domain and (2) records the envelope
2303 information in a special header (X\-Original\-To, Delivered\-To,
2304 X\-Envelope\-To).\fR
2306 .SS Good Ways To Use Multidrop Mailboxes
2307 Multiple local names can be used to administer a mailing list from the
2308 client side of a \fIfetchmail\fR collection. Suppose your name is
2309 \&'esr', and you want to both pick up your own mail and maintain a mailing
2310 list called (say) "fetchmail-friends", and you want to keep the alias
2311 list on your client machine.
2313 On your server, you can alias 'fetchmail\-friends' to 'esr'; then, in
2314 your \fI.fetchmailrc\fR, declare 'to esr fetchmail\-friends here'.
2315 Then, when mail including 'fetchmail\-friends' as a local address
2316 gets fetched, the list name will be appended to the list of
2317 recipients your SMTP listener sees. Therefore it will undergo alias
2318 expansion locally. Be sure to include 'esr' in the local alias
2319 expansion of fetchmail\-friends, or you'll never see mail sent only to
2320 the list. Also be sure that your listener has the "me-too" option set
2321 (sendmail's \-oXm command-line option or OXm declaration) so your name
2322 isn't removed from alias expansions in messages you send.
2324 This trick is not without its problems, however. You'll begin to see
2325 this when a message comes in that is addressed only to a mailing list
2326 you do \fInot\fR have declared as a local name. Each such message
2327 will feature an 'X\-Fetchmail\-Warning' header which is generated
2328 because fetchmail cannot find a valid local name in the recipient
2329 addresses. Such messages default (as was described above) to being
2330 sent to the local user running
2332 but the program has no way to know that that's actually the right thing.
2334 .SS Bad Ways To Abuse Multidrop Mailboxes
2335 Multidrop mailboxes and
2337 serving multiple users in daemon mode do not mix. The problem, again, is
2338 mail from mailing lists, which typically does not have an individual
2339 recipient address on it. Unless
2341 can deduce an envelope address, such mail will only go to the account
2342 running fetchmail (probably root). Also, blind-copied users are very
2343 likely never to see their mail at all.
2345 If you're tempted to use
2347 to retrieve mail for multiple users from a single mail drop via POP or
2348 IMAP, think again (and reread the section on header and envelope
2349 addresses above). It would be smarter to just let the mail sit in the
2350 mailserver's queue and use fetchmail's ETRN or ODMR modes to trigger
2351 SMTP sends periodically (of course, this means you have to poll more
2352 frequently than the mailserver's expiry period). If you can't arrange
2353 this, try setting up a UUCP feed.
2355 If you absolutely \fImust\fR use multidrop for this purpose, make sure
2356 your mailserver writes an envelope-address header that fetchmail can
2357 see. Otherwise you \fIwill\fR lose mail and it \fIwill\fR come back
2360 .SS Speeding Up Multidrop Checking
2361 Normally, when multiple users are declared
2363 extracts recipient addresses as described above and checks each host
2364 part with DNS to see if it's an alias of the mailserver. If so, the
2365 name mappings described in the "to ... here" declaration are done and
2366 the mail locally delivered.
2368 This is a convenient but also slow method. To speed
2369 it up, pre-declare mailserver aliases with 'aka'; these are checked
2370 before DNS lookups are done. If you're certain your aka list contains
2372 DNS aliases of the mailserver (and all MX names pointing at it - note
2373 this may change in a future version)
2374 you can declare 'no dns' to suppress DNS lookups entirely and
2375 \fIonly\fR match against the aka list.
2378 To facilitate the use of
2380 in shell scripts, an exit code is returned to give an indication
2381 of what occurred during a given connection.
2383 The exit codes returned by
2387 One or more messages were successfully retrieved (or, if the \-c option
2388 was selected, were found waiting but not retrieved).
2390 There was no mail awaiting retrieval. (There may have been old mail still
2391 on the server but not selected for retrieval.)
2393 An error was encountered when attempting to open a socket to retrieve
2394 mail. If you don't know what a socket is, don't worry about it --
2395 just treat this as an 'unrecoverable error'. This error can also be
2396 because a protocol fetchmail wants to use is not listed in /etc/services.
2398 The user authentication step failed. This usually means that a bad
2399 user-id, password, or APOP id was specified. Or it may mean that you
2400 tried to run fetchmail under circumstances where it did not have
2401 standard input attached to a terminal and could not prompt for a
2404 Some sort of fatal protocol error was detected.
2406 There was a syntax error in the arguments to
2409 The run control file had bad permissions.
2411 There was an error condition reported by the server. Can also
2414 timed out while waiting for the server.
2416 Client-side exclusion error. This means
2418 either found another copy of itself already running, or failed in such
2419 a way that it isn't sure whether another copy is running.
2421 The user authentication step failed because the server responded "lock
2422 busy". Try again after a brief pause! This error is not implemented
2423 for all protocols, nor for all servers. If not implemented for your
2424 server, "3" will be returned instead, see above. May be returned when
2425 talking to qpopper or other servers that can respond with "lock busy"
2426 or some similar text containing the word "lock".
2430 run failed while trying to do an SMTP port open or transaction.
2432 Fatal DNS error. Fetchmail encountered an error while performing
2433 a DNS lookup at startup and could not proceed.
2435 BSMTP batch file could not be opened.
2437 Poll terminated by a fetch limit (see the \-\-fetchlimit option).
2439 Server busy indication.
2441 Server timed out during an IMAP IDLE.
2443 Internal error. You should see a message on standard error with
2448 queries more than one host, return status is 0 if \fIany\fR query
2449 successfully retrieved mail. Otherwise the returned error status is
2450 that of the last host queried.
2455 default run control file
2458 default location of file associating hosts with last message IDs seen
2459 (used only with newer RFC1939-compliant POP3 servers supporting the
2463 lock file to help prevent concurrent runs (non-root mode).
2466 your FTP run control file, which (if present) will be searched for
2467 passwords as a last resort before prompting for one interactively.
2469 /var/run/fetchmail.pid
2470 lock file to help prevent concurrent runs (root mode, Linux systems).
2473 lock file to help prevent concurrent runs (root mode, systems without /var/run).
2476 If the FETCHMAILUSER variable is set, it is used as the name of the
2477 calling user (default local name) for purposes such as mailing error
2478 notifications. Otherwise, if either the LOGNAME or USER variable is
2479 correctly set (e.g. the corresponding UID matches the session user ID)
2480 then that name is used as the default local name. Otherwise
2481 \fBgetpwuid\fR(3) must be able to retrieve a password entry for the
2482 session ID (this elaborate logic is designed to handle the case of
2483 multiple names per userid gracefully).
2485 If the environment variable FETCHMAILHOME is set to a valid and
2486 existing directory name, fetchmail will read $FETCHMAILHOME/fetchmailrc
2487 (the dot is missing in this case), $FETCHMAILHOME/.fetchids and
2488 $FETCHMAILHOME/.fetchmail.pid rather than from the user's home
2489 directory. The .netrc file is always looked for in the the invoking
2490 user's home directory regardless of FETCHMAILHOME's setting.
2492 If the HOME_ETC variable is set, fetchmail will read
2493 $HOME_ETC/.fetchmailrc instead of ~/.fetchmailrc.
2495 If HOME_ETC and FETCHMAILHOME are set, HOME_ETC will be ignored.
2500 daemon is running as root, SIGHUP wakes it up from its sleep phase and
2501 forces a poll of all non-skipped servers (this is in accordance with
2502 the usual conventions for system daemons).
2506 is running in daemon mode as non-root, use SIGUSR1 to wake it (this is
2507 so SIGHUP due to logout can retain the default action of killing it).
2511 in foreground while a background fetchmail is running will do
2512 whichever of these is appropriate to wake it up.
2514 .SH BUGS AND KNOWN PROBLEMS
2516 Fetchmail cannot handle user names that contain blanks after a "@"
2517 character, for instance "demonstr@ti on". These are rather uncommon and
2518 only hurt when using UID-based --keep setups, so the 6.3.X versions of
2519 fetchmail won't be fixed.
2521 Please check the \fBNEWS\fP file that shipped with fetchmail for more
2522 known bugs than those listed here.
2524 The assumptions that the DNS and in particular the checkalias options
2525 make are not often sustainable. For instance, it has become uncommon for
2526 an MX server to be a POP3 or IMAP server at the same time. Therefore the
2527 MX lookups may go away in a future release.
2529 The mda and plugin options interact badly. In order to collect error
2530 status from the MDA, fetchmail has to change its normal signal
2531 handling so that dead plugin processes don't get reaped until the end
2532 of the poll cycle. This can cause resource starvation if too many
2533 zombies accumulate. So either don't deliver to a MDA using plugins or
2534 risk being overrun by an army of undead.
2536 The \-\-interface option does not support IPv6 and it is doubtful if it
2537 ever will, since there is no portable way to query interface IPv6
2540 The RFC822 address parser used in multidrop mode chokes on some
2541 @-addresses that are technically legal but bizarre. Strange uses of
2542 quoting and embedded comments are likely to confuse it.
2544 In a message with multiple envelope headers, only the last one
2545 processed will be visible to fetchmail.
2547 Use of some of these protocols requires that the program send
2548 unencrypted passwords over the TCP/IP connection to the mailserver.
2549 This creates a risk that name/password pairs might be snaffled with a
2550 packet sniffer or more sophisticated monitoring software. Under Linux
2551 and FreeBSD, the \-\-interface option can be used to restrict polling to
2552 availability of a specific interface device with a specific local or
2553 remote IP address, but snooping is still possible if (a) either host
2554 has a network device that can be opened in promiscuous mode, or (b)
2555 the intervening network link can be tapped. We recommend the use of
2557 tunnelling to not only shroud your passwords but encrypt the entire
2560 Use of the %F or %T escapes in an mda option could open a security
2561 hole, because they pass text manipulable by an attacker to a shell
2562 command. Potential shell characters are replaced by '_' before
2563 execution. The hole is further reduced by the fact that fetchmail
2564 temporarily discards any suid privileges it may have while running the
2565 MDA. For maximum safety, however, don't use an mda command containing
2566 %F or %T when fetchmail is run from the root account itself.
2568 Fetchmail's method of sending bounces due to errors or spam-blocking and
2569 spam bounces requires that port 25 of localhost be available for sending
2574 while a background instance is running and break the syntax, the
2575 background instance will die silently. Unfortunately, it can't
2576 die noisily because we don't yet know whether syslog should be enabled.
2577 On some systems, fetchmail dies quietly even if there is no syntax
2578 error; this seems to have something to do with buggy terminal ioctl
2581 The \-f\~\- option (reading a configuration from stdin) is incompatible
2582 with the plugin option.
2584 The 'principal' option only handles Kerberos IV, not V.
2586 Interactively entered passwords are truncated after 63 characters. If
2587 you really need to use a longer password, you will have to use a
2590 A backslash as the last character of a configuration file will be
2591 flagged as a syntax error rather than ignored.
2593 Send comments, bug reports, gripes, and the like to the
2594 fetchmail\-devel list <fetchmail\-devel@lists.berlios.de>. An HTML FAQ is
2595 available at the fetchmail home page; surf to
2596 http://fetchmail.berlios.de/ or do a WWW search for pages with
2597 \&'fetchmail' in their titles.
2600 Fetchmail is currently maintained by Matthias Andree and Rob Funk with
2601 major assistance from Sunil Shetye (for code) and Rob MacGregor (for the
2604 Most of the code is from Eric S. Raymond <esr@snark.thyrsus.com>. Too
2605 many other people to name here have contributed code and patches.
2607 This program is descended from and replaces
2609 by Carl Harris <ceharris@mal.com>; the internals have become quite different,
2610 but some of its interface design is directly traceable to that
2613 This manual page has been improved by R.\ Hannes Beinert and H\['e]ctor
2617 mutt(1), elm(1), mail(1), sendmail(8), popd(8), imapd(8), netrc(5)
2619 The fetchmail home page: <http://fetchmail.berlios.de/>
2621 The maildrop home page: <http://www.courier-mta.org/maildrop/>
2622 .SH APPLICABLE STANDARDS
2624 Note that this list is just a collection of references and not a
2625 statement as to the actual protocol conformance or requirements in
2629 RFC 821, RFC 2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC 1985,
2633 RFC 822, RFC 2822, RFC 1123, RFC 1892, RFC 1894.
2639 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC 1734, RFC 1939, RFC 1957,
2643 RFC 1460, RFC 1725, RFC 1939.
2652 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC 2177,
projects / ~andy / fetchmail / blob