2 .\" ** The above line should force tbl to be used as a preprocessor **
4 .\" Manual page in man(7) format with tbl(1) macros for fetchmail
6 .\" For license terms, see the file COPYING in this directory.
10 fetchmail \- fetch mail from a POP, IMAP, ETRN, or ODMR-capable server
13 \fBfetchmail\fR [\fIoption...\fR] [\fImailserver...\fR]
19 is a mail-retrieval and forwarding utility; it fetches mail from
20 remote mailservers and forwards it to your local (client) machine's
21 delivery system. You can then handle the retrieved mail using normal
22 mail user agents such as \fImutt\fR(1), \fIelm\fR(1) or \fIMail\fR(1).
23 The \fIfetchmail\fR utility can be run in a daemon mode to repeatedly
24 poll one or more systems at a specified interval.
28 program can gather mail from servers supporting any of the common
29 mail-retrieval protocols: POP2, POP3, IMAP2bis, IMAP4, and IMAP4rev1.
30 It can also use the ESMTP ETRN extension and ODMR. (The RFCs describing all
31 these protocols are listed at the end of this manual page.)
35 is primarily intended to be used over on-demand TCP/IP links (such as
36 SLIP or PPP connections), it may also be useful as a message transfer
37 agent for sites which refuse for security reasons to permit
38 (sender-initiated) SMTP transactions with sendmail.
42 is used with a POP or an IMAP server, it has two fundamental modes of
43 operation for each user account from which it retrieves mail:
44 \fIsingledrop\fR- and \fImultidrop\fR-mode. In singledrop-mode,
46 assumes that all messages in the user's account are intended for a single
47 recipient. An individual mail message will not be inspected for recipient
48 information, rather, the identity of the recipient will either default to
49 the local user currently executing \fIfetchmail\fR,
50 or else will need to be explicitly specified in the configuration file.
51 Singledrop-mode is used when the fetchmailrc configuration contains at
52 most a single local user specification for a given server account.
56 is not able to assume that there is only a single recipient, but rather
57 that the mail server account actually contains mail intended for any
58 number of different recipients. Therefore,
60 must attempt to deduce the proper "envelope recipient" from the mail
61 headers of each message. In this mode of operation
63 almost resembles an MTA, however it is important to note that neither
64 the POP nor IMAP protocols were intended for use in this fashion, and
65 hence envelope information is not directly available. Instead,
67 must resort to a process of informed guess-work in an attempt to
68 discover the true envelope recipient of a message. Even if this
69 information is present in the headers, the process can
70 be error-prone and is dependent upon the specific mail server used
71 for mail retrieval. Multidrop-mode is used when more than one local
72 user is specified for a particular server account in the configuration
73 file. Note that the forgoing discussion of singledrop- and
74 multidrop-modes does not apply to the ESMTP ETRN or ODMR retrieval
75 methods, since they are based upon the SMTP protocol which
76 specifically provides the envelope recipient to \fIfetchmail\fR.
78 As each message is retrieved \fIfetchmail\fR normally delivers it via SMTP to
79 port 25 on the machine it is running on (localhost), just as though it
80 were being passed in over a normal TCP/IP link. \fIfetchmail\fR provides
81 the SMTP server with an envelope recipient derived in the manner described
82 previously. The mail will then be
83 delivered locally via your system's MDA (Mail Delivery Agent, usually
84 \fIsendmail\fR(8) but your system may use a different one such
85 as \fIsmail\fR, \fImmdf\fR, \fIexim\fR, \fIpostfix\fR, or \fIqmail\fR). All the
86 delivery-control mechanisms (such as \fI.forward\fR files) normally
87 available through your system MDA and local delivery agents will
88 therefore work automatically.
90 If no port 25 listener is available, but your fetchmail configuration
91 was told about a reliable local MDA, it will use that MDA for local
96 is available, it will assist you in setting up and editing a
97 fetchmailrc configuration. It runs under the X window system and
98 requires that the language Python and the Tk toolkit be present on your
99 system. If you are first setting up fetchmail for single-user mode, it
100 is recommended that you use Novice mode. Expert mode provides complete
101 control of fetchmail configuration, including the multidrop features.
102 In either case, the 'Autoprobe' button will tell you the most capable
103 protocol a given mailserver supports, and warn you of potential problems
106 .SH GENERAL OPERATION
109 is controlled by command-line options and a run control file,
110 .IR ~/.fetchmailrc\fR ,
111 the syntax of which we describe in a later section (this file is what
112 the \fIfetchmailconf\fR program edits). Command-line options override
116 Each server name that you specify following the options on the
117 command line will be queried. If you don't specify any servers
118 on the command line, each 'poll' entry in your
120 file will be queried.
122 To facilitate the use of
124 in scripts and pipelines, it returns an appropriate exit code upon
125 termination -- see EXIT CODES below.
127 The following options modify the behavior of \fIfetchmail\fR. It is
128 seldom necessary to specify any of these once you have a
129 working \fI.fetchmailrc\fR file set up.
131 Almost all options have a corresponding keyword which can be used to
136 Some special options are not covered here, but are documented instead
137 in sections on AUTHENTICATION and DAEMON MODE which follow.
141 Displays the version information for your copy of
143 No mail fetch is performed.
144 Instead, for each server specified, all the option information
145 that would be computed if
147 were connecting to that server is displayed. Any non-printables in
148 passwords or other string names are shown as backslashed C-like
149 escape sequences. This option is useful for verifying that your
150 options are set the way you want them.
153 Return a status code to indicate whether there is mail waiting,
154 without actually fetching or deleting mail (see EXIT CODES below).
155 This option turns off daemon mode (in which it would be useless). It
156 doesn't play well with queries to multiple sites, and doesn't work
157 with ETRN or ODMR. It will return a false positive if you leave read but
158 undeleted mail in your server mailbox and your fetch protocol can't
159 tell kept messages from new ones. This means it will work with IMAP,
160 not work with POP2, and may occasionally flake out under POP3.
163 Silent mode. Suppresses all progress/status messages that are
164 normally echoed to standard output during a fetch (but does not
165 suppress actual error messages). The --verbose option overrides this.
168 Verbose mode. All control messages passed between
170 and the mailserver are echoed to stdout. Overrides --silent.
171 Doubling this option (-v -v) causes extra diagnostic information
177 Retrieve both old (seen) and new messages from the mailserver. The
178 default is to fetch only messages the server has not marked seen.
179 Under POP3, this option also forces the use of RETR rather than TOP.
180 Note that POP2 retrieval behaves as though --all is always on (see
181 RETRIEVAL FAILURE MODES below) and this option does not work with ETRN
186 Keep retrieved messages on the remote mailserver. Normally, messages
187 are deleted from the folder on the mailserver after they have been retrieved.
190 option causes retrieved messages to remain in your folder on the
191 mailserver. This option does not work with ETRN or ODMR.
195 Delete retrieved messages from the remote mailserver. This
196 option forces retrieved mail to be deleted. It may be useful if
197 you have specified a default of \fBkeep\fR in your
198 \&\fI.fetchmailrc\fR. This option is forced on with ETRN and ODMR.
201 POP3/IMAP only. This is a dangerous option and can cause mail loss when
202 used improperly. It deletes old (seen) messages from the mailserver
203 before retrieving new messages. Warning: This can cause mail loss if
204 you check your mail with other clients than fetchmail, and cause
205 fetchmail to delete a message it had never fetched before. Similarly, if
206 your local MTA hangs and fetchmail is aborted, the next time you run
207 fetchmail, it will delete mail that was never delivered to you. You
208 should probably not use this option in your configuration file. What you
209 probably want is the default setting: if you don't specify '-k', then
210 fetchmail will automatically delete messages after successful
211 delivery. This option does not work with ETRN and ODMR.
214 POP3/IMAP only, since version 6.3.0. Delete oversized messages from the
215 mailserver before retrieving new messages. The size limit should be
216 separately sepecified with the --limit option. This option does not
217 work with ETRN or ODMR.
218 .SS Protocol and Query Options
220 .B \-p <proto> | \-\-proto <proto> | \-\-protocol <proto>
221 (Keyword: proto[col])
222 Specify the protocol to use when communicating with the remote
223 mailserver. If no protocol is specified, the default is AUTO.
225 may be one of the following:
228 Tries IMAP, POP3, and POP2 (skipping any of these for which support
229 has not been compiled in).
231 Post Office Protocol 2
233 Post Office Protocol 3
235 Use POP3 with old-fashioned MD5-challenge authentication.
237 Use POP3 with RPOP authentication.
239 Use POP3 with Kerberos V4 authentication on port 1109.
241 Use POP3 with Demon Internet's SDPS extensions.
243 IMAP2bis, IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities).
245 Use the ESMTP ETRN option.
247 Use the the On-Demand Mail Relay ESMTP profile.
250 All these alternatives work in basically the same way (communicating
251 with standard server daemons to fetch mail already delivered to a
252 mailbox on the server) except ETRN and ODMR. The ETRN mode
253 allows you to ask a compliant ESMTP server (such as BSD sendmail at
254 release 8.8.0 or higher) to immediately open a sender-SMTP connection
255 to your client machine and begin forwarding any items addressed to
256 your client machine in the server's queue of undelivered mail. The
257 ODMR mode requires an ODMR-capable server and works similarly to
258 ETRN, except that it does not require the client machine to have
263 Force UIDL use (effective only with POP3). Force client-side tracking
264 of 'newness' of messages (UIDL stands for "unique ID listing" and is
265 described in RFC1939). Use with 'keep' to use a mailbox as a baby
266 news drop for a group of users. The fact that seen messages are skipped
267 is logged, unless error logging is done through syslog while running in
268 daemon mode. Note that fetchmail may automatically enable this option
269 depending on upstream server capabilities. Note also that this option
270 may be removed and forced enabled in a future fetchmail version.
273 .B \-\-service <servicename>
274 (Keyword: service) Since version 6.3.0.
275 The service option permits you to specify a service name to connect to.
276 You can specify a decimal port number here, if your services database
277 lacks the required service-port assignments. See the FAQ item R12 and
278 the \-\-ssl documentation for details. This replaces the older \-\-port
281 .B \-P <portnumber> | \-\-port <portnumber>
283 Obsolete version of \-\-service that does not take service names.
285 this option may be removed from a future version.
287 .B \-\-principal <principal>
289 The principal option permits you to specify a service principal for
290 mutual authentication. This is applicable to POP3 or IMAP with Kerberos
293 .B \-t <seconds> | \-\-timeout <seconds>
295 The timeout option allows you to set a server-nonresponse
296 timeout in seconds. If a mailserver does not send a greeting message
297 or respond to commands for the given number of seconds,
298 \fIfetchmail\fR will hang up on it. Without such a timeout
299 \fIfetchmail\fR might hang up indefinitely trying to fetch mail from a
300 down host. This would be particularly annoying for a \fIfetchmail\fR
301 running in background. There is a default timeout which fetchmail\~-V
302 will report. If a given connection receives too many timeouts in
303 succession, fetchmail will consider it wedged and stop retrying,
304 the calling user will be notified by email if this happens.
306 .B \-\-plugin <command>
307 (Keyword: plugin) The plugin option allows you to use an external
308 program to establish the TCP connection. This is useful if you want
309 to use socks, SSL, ssh, or need some special firewalling setup. The
310 program will be looked up in $PATH and can optionally be passed the
311 hostname and port as arguments using "%h" and "%p" respectively (note
312 that the interpolation logic is rather primitive, and these token must
313 be bounded by whitespace or beginning of string or end of string).
314 Fetchmail will write to the plugin's stdin and read from the plugin's
317 .B \-\-plugout <command>
319 Identical to the plugin option above, but this one is used for the SMTP
320 connections (which will probably not need it, so it has been separated
323 .B \-r <name> | \-\-folder <name>
325 Causes a specified non-default mail folder on the mailserver (or
326 comma-separated list of folders) to be retrieved. The syntax of the
327 folder name is server-dependent. This option is not available under
331 (Keyword: tracepolls)
332 Tell fetchmail to poll trace information in the form 'polling %s
333 account %s' to the Received line it generates, where the %s parts are
334 replaced by the user's remote name and the poll label (the Received
335 header also normally includes the server's true name). This can be
336 used to facilitate mail filtering based on the account it is being
341 Causes the connection to the mail server to be encrypted via SSL. Connect
342 to the server using the specified base protocol over a connection secured
343 by SSL. SSL support must be present at the server.
345 If no port is specified, the connection is attempted to the well known
346 port of the SSL version of the base protocol. This is generally a
347 different port than the port used by the base protocol. For IMAP, this
348 is port 143 for the clear protocol and port 993 for the SSL secured
349 protocol, for POP3, it is port 110 for the cleartext and port 995 for
350 the encrypted variant.
352 If your system lacks the corresponding entries from /etc/services, see
353 the \-\-service option and specify the numeric port number as given in
354 the previous paragraph (unless your ISP had directed you to different
355 ports, which is uncommon however).
357 .B \-\-sslcert <name>
359 Specifies the file name of the client side public SSL certificate. Some
360 SSL encrypted servers may require client side keys and certificates for
361 authentication. In most cases, this is optional. This specifies
362 the location of the public key certificate to be presented to the server
363 at the time the SSL session is established. It is not required (but may
364 be provided) if the server does not require it. Some servers may
365 require it, some servers may request it but not require it, and some
366 servers may not request it at all. It may be the same file
367 as the private key (combined key and certificate file) but this is not
372 Specifies the file name of the client side private SSL key. Some SSL
373 encrypted servers may require client side keys and certificates for
374 authentication. In most cases, this is optional. This specifies
375 the location of the private key used to sign transactions with the server
376 at the time the SSL session is established. It is not required (but may
377 be provided) if the server does not require it. Some servers may
378 require it, some servers may request it but not require it, and some
379 servers may not request it at all. It may be the same file
380 as the public key (combined key and certificate file) but this is not
381 recommended. If a password is required to unlock the key, it will be
382 prompted for at the time just prior to establishing the session to the
383 server. This can cause some complications in daemon mode.
385 .B \-\-sslproto <name>
387 Forces an SSL protocol. Possible values are '\fBssl2\fR',
388 \&'\fBssl3\fR', '\fBssl23\fR', and '\fBtls1\fR'. Try this if the default
389 handshake does not work for your server. To defeat automatic TLSv1
390 negotiation when the server advertises STARTTLS or STLS, use \fB''\fR or
391 \&'\fBssl23\fR'. The default is to try appropriate protocols depending
396 Causes fetchmail to strictly check the server certificate against a set of
397 local trusted certificates (see the \fBsslcertpath\fR option). If the server
398 certificate is not signed by one of the trusted ones (directly or indirectly),
399 the SSL connection will fail. This checking should prevent man-in-the-middle
400 attacks against the SSL connection. Note that CRLs are seemingly not currently
401 supported by OpenSSL in certificate verification! Your system clock should
402 be reasonably accurate when using this option!
404 .B \-\-sslcertpath <directory>
405 (Keyword: sslcertpath)
406 Sets the directory fetchmail uses to look up local certificates. The default
407 is your OpenSSL default one. The directory must be hashed as OpenSSL expects
408 it - every time you add or modify a certificate in the directory, you need
409 to use the \fBc_rehash\fR tool (which comes with OpenSSL in the tools/
412 .B \-\-sslfingerprint <fingerprint>
413 (Keyword: sslfingerprint)
414 Specify the fingerprint of the server key (an MD5 hash of the key) in
415 hexadecimal notation with colons separating groups of two digits. The letter
416 hex digits must be in upper case. This is the default format OpenSSL uses,
417 and the one fetchmail uses to report the fingerprint when an SSL connection
418 is established. When this is specified, fetchmail will compare the server key
419 fingerprint with the given one, and the connection will fail if they do not
420 match. This can be used to prevent man-in-the-middle attacks.
421 .SS Delivery Control Options
423 .B \-S <hosts> | \-\-smtphost <hosts>
424 (Keyword: smtp[host])
425 Specify a hunt list of hosts to forward mail to (one or more
426 hostnames, comma-separated). Hosts are tried in list order; the first
427 one that is up becomes the forwarding target for the current run.
428 Normally, 'localhost' is added to the end of the list as an invisible
429 default. However, when using Kerberos authentication, the FQDN of the
430 machine running fetchmail is added to the end of the list as an
431 invisible default. Each hostname may have a port number following the
432 host name. The port number is separated from the host name by a
433 slash; the default port is 25 (or "smtp" under IPv6). If you
434 specify an absolute path name (beginning with a /), it will be
435 interpreted as the name of a UNIX socket accepting LMTP connections
436 (such as is supported by the Cyrus IMAP daemon) Example:
439 --smtphost server1,server2/2525,server3,/var/imap/socket/lmtp
442 This option can be used with ODMR, and will make fetchmail a relay
443 between the ODMR server and SMTP or LMTP receiver.
445 .B \-\-fetchdomains <hosts>
446 (Keyword: fetchdomains)
447 In ETRN or ODMR mode, this option specifies the list of domains the
448 server should ship mail for once the connection is turned around. The
449 default is the FQDN of the machine running
452 .B \-D <domain> | \-\-smtpaddress <domain>
453 (Keyword: smtpaddress) Specify the domain to be appended to addresses
454 in RCPT TO lines shipped to SMTP. The name of the SMTP server (as
455 specified by --smtphost, or defaulted to "localhost") is used when
456 this is not specified.
458 .B \-\-smtpname <user@domain>
460 Specify the domain and user to be put in RCPT TO lines shipped to SMTP.
461 The default user is the current local user.
463 .B \-Z <nnn> | \-\-antispam <nnn[, nnn]...>
465 Specifies the list of numeric SMTP errors that are to be interpreted
466 as a spam-block response from the listener. A value of -1 disables
467 this option. For the command-line option, the list values should
470 .B \-m <command> | \-\-mda <command>
471 (Keyword: mda) You can force mail to be passed to an MDA directly
472 (rather than forwarded to port 25) with the --mda or -m option. To
473 avoid losing mail, use this option only with MDAs like maildrop, procmail or
474 sendmail that return a nonzero status on disk-full and other
475 resource-exhaustion errors; the nonzero status tells fetchmail that
476 delivery failed and prevents the message from being deleted off the
477 server. If \fIfetchmail\fR is running as root, it sets its user id to
478 that of the target user while delivering mail through an MDA. Some
479 possible MDAs are "/usr/sbin/sendmail -i -f %F %T", "/usr/bin/deliver"
480 and "/usr/bin/procmail -d %T" (but the latter is usually redundant as
481 it's what SMTP listeners normally forward to). Local delivery
482 addresses will be inserted into the MDA command wherever you place a
483 %T; the mail message's From address will be inserted where you place
484 an %F. \fBDO NOT ENCLOSE THE %F OR %T STRING IN SINGLE QUOTES!\fR For
485 both %T and %F, fetchmail encloses the addresses in single quotes ('),
486 after removing any single quotes they may contain, before the MDA
487 command is passed to the shell. Do \fINOT\fR use an MDA invocation
488 like "sendmail -i -t" that dispatches on the contents of To/Cc/Bcc, it
489 will create mail loops and bring the just wrath of many postmasters
490 down upon your head. Also, do \fInot\fR try to combine multidrop
491 mode with an MDA such as procmail that can only accept one address;
496 Cause delivery via LMTP (Local Mail Transfer Protocol). A service
497 port \fImust\fR be explicitly specified (with a slash suffix) on each
498 host in the smtphost hunt list if this option is selected; the
499 default port 25 will (in accordance with RFC 2033) not be accepted.
501 .B \-\-bsmtp <filename>
503 Append fetched mail to a BSMTP file. This simply contains the SMTP
504 commands that would normally be generated by fetchmail when passing
505 mail to an SMTP listener daemon. An argument of '-' causes the mail
506 to be written to standard output. Note that fetchmail's
507 reconstruction of MAIL FROM and RCPT TO lines is not guaranteed
508 correct; the caveats discussed under THE USE AND ABUSE OF MULTIDROP
509 MAILBOXES below apply.
510 .SS Resource Limit Control Options
512 .B \-l <maxbytes> | \-\-limit <maxbytes>
513 (Keyword: limit) Takes a maximum octet size argument. Messages larger
514 than this size will not be fetched and will be left on the server (in
515 foreground sessions, the progress messages will note that they are
516 "oversized"). If the fetch protocol permits (in particular, under
517 IMAP or POP3 without the fetchall option) the message will not be
520 An explicit --limit of 0 overrides any limits set in your
521 run control file. This option is intended for those needing to
522 strictly control fetch time due to expensive and variable phone rates.
524 Combined with --limitflush, it can be used to delete oversized
525 messages waiting on a server. In daemon mode, oversize notifications
526 are mailed to the calling user (see the --warnings option). This
527 option does not work with ETRN or ODMR.
529 .B \-w <interval> | \-\-warnings <interval>
531 Takes an interval in seconds. When you call
533 with a 'limit' option in daemon mode, this controls the interval at
534 which warnings about oversized messages are mailed to the calling user
535 (or the user specified by the 'postmaster' option). One such
536 notification is always mailed at the end of the the first poll that
537 the oversized message is detected. Thereafter, renotification is
538 suppressed until after the warning interval elapses (it will take
539 place at the end of the first following poll).
541 .B \-b <count> | \-\-batchlimit <count>
542 (Keyword: batchlimit)
543 Specify the maximum number of messages that will be shipped to an SMTP
544 listener before the connection is deliberately torn down and rebuilt
545 (defaults to 0, meaning no limit). An explicit --batchlimit of 0
546 overrides any limits set in your run control file. While
547 \fBsendmail\fR(8) normally initiates delivery of a message immediately
548 after receiving the message terminator, some SMTP listeners are not so
549 prompt. MTAs like \fIsmail\fR(8) may wait till the
550 delivery socket is shut down to deliver. This may produce annoying
551 delays when \fIfetchmail\fR is processing very large batches. Setting
552 the batch limit to some nonzero size will prevent these delays. This
553 option does not work with ETRN or ODMR.
555 .B \-B <number> | \-\-fetchlimit <number>
556 (Keyword: fetchlimit)
557 Limit the number of messages accepted from a given server in a single
558 poll. By default there is no limit. An explicit --fetchlimit of 0
559 overrides any limits set in your run control file.
560 This option does not work with ETRN or ODMR.
562 .B \-\-fetchsizelimit <number>
563 (Keyword: fetchsizelimit)
564 Limit the number of sizes of messages accepted from a given server in
565 a single transaction. This option is useful in reducing the delay in
566 downloading the first mail when there are too many mails in the
567 mailbox. By default, the limit is 100. If set to 0, sizes of all
568 messages are downloaded at the start.
569 This option does not work with ETRN or ODMR. For POP3, the only valid
572 .B \-\-fastuidl <number>
574 Do a binary instead of linear search for the first unseen UID. Binary
575 search avoids downloading the UIDs of all mails. This saves time
576 (especially in daemon mode) where downloading the same set of UIDs in
577 each poll is a waste of bandwidth. The number 'n' indicates how rarely
578 a linear search should be done. In daemon mode, linear search is used
579 once followed by binary searches in 'n-1' polls if 'n' is greater than
580 1; binary search is always used if 'n' is 1; linear search is always
581 used if 'n' is 0. In non-daemon mode, binary search is used if 'n' is
582 1; otherwise linear search is used.
583 This option works with POP3 only.
585 .B \-e <count> | \-\-expunge <count>
587 Arrange for deletions to be made final after a given number of
588 messages. Under POP2 or POP3, fetchmail cannot make deletions final
589 without sending QUIT and ending the session -- with this option on,
590 fetchmail will break a long mail retrieval session into multiple
591 sub-sessions, sending QUIT after each sub-session. This is a good
592 defense against line drops on POP3 servers that do not do the
593 equivalent of a QUIT on hangup. Under IMAP,
595 normally issues an EXPUNGE command after each deletion in order to
596 force the deletion to be done immediately. This is safest when your
597 connection to the server is flaky and expensive, as it avoids
598 resending duplicate mail after a line hit. However, on large
599 mailboxes the overhead of re-indexing after every message can slam the
600 server pretty hard, so if your connection is reliable it is good to do
601 expunges less frequently. Also note that some servers enforce a delay
602 of a few seconds after each quit, so fetchmail may not be able to get
603 back in immediately after an expunge -- you may see "lock busy" errors
604 if this happens. If you specify this option to an integer N,
607 to only issue expunges on every Nth delete. An argument of zero
608 suppresses expunges entirely (so no expunges at all will be done until
609 the end of run). This option does not work with ETRN or ODMR.
610 .SS Authentication Options
612 .B \-u <name> | \-\-user <name> | \-\-username <name>
613 (Keyword: user[name])
614 Specifies the user identification to be used when logging in to the mailserver.
615 The appropriate user identification is both server and user-dependent.
616 The default is your login name on the client machine that is running
618 See USER AUTHENTICATION below for a complete description.
620 .B \-I <specification> | \-\-interface <specification>
622 Require that a specific interface device be up and have a specific local
623 or remote IPv4 (IPv6 is not supported by this option yet) address (or
624 range) before polling. Frequently \fIfetchmail\fP
625 is used over a transient point-to-point TCP/IP link established directly
626 to a mailserver via SLIP or PPP. That is a relatively secure channel.
627 But when other TCP/IP routes to the mailserver exist (e.g. when the link
628 is connected to an alternate ISP), your username and password may be
629 vulnerable to snooping (especially when daemon mode automatically polls
630 for mail, shipping a clear password over the net at predictable
631 intervals). The --interface option may be used to prevent this. When
632 the specified link is not up or is not connected to a matching IP
633 address, polling will be skipped. The format is:
636 interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]
639 The field before the first slash is the interface name (i.e. sl0, ppp0
640 etc.). The field before the second slash is the acceptable IP address.
641 The field after the second slash is a mask which specifies a range of
642 IP addresses to accept. If no mask is present 255.255.255.255 is
643 assumed (i.e. an exact match). This option is currently only supported
644 under Linux and FreeBSD. Please see the
646 section for below for FreeBSD specific information.
648 Note that this option may be removed from a future fetchmail version.
650 .B \-M <interface> | \-\-monitor <interface>
652 Daemon mode can cause transient links which are automatically taken down
653 after a period of inactivity (e.g. PPP links) to remain up
654 indefinitely. This option identifies a system TCP/IP interface to be
655 monitored for activity. After each poll interval, if the link is up but
656 no other activity has occurred on the link, then the poll will be
657 skipped. However, when fetchmail is woken up by a signal, the
658 monitor check is skipped and the poll goes through unconditionally.
659 This option is currently only supported under Linux and FreeBSD.
664 options to work for non root users under FreeBSD, the fetchmail binary
665 must be installed SGID kmem. This would be a security hole, but
666 fetchmail runs with the effective GID set to that of the kmem group
668 when interface data is being collected.
670 Note that this option may be removed from a future fetchmail version.
673 (Keyword: auth[enticate])
674 This option permits you to specify an authentication type (see USER
675 AUTHENTICATION below for details). The possible values are \fBany\fR,
676 \&\fBpassword\fR, \fBkerberos_v5\fR, \fBkerberos\fR (or, for
677 excruciating exactness, \fBkerberos_v4\fR), \fBgssapi\fR,
678 \fBcram-md5\fR, \fBotp\fR, \fBntlm\fR, \fBmsn\fR (only for POP3) and
679 \fBssh\fR. When \fBany\fR (the default) is specified, fetchmail tries
680 first methods that don't require a password (GSSAPI, KERBEROS\ IV,
681 KERBEROS\ 5); then it looks for methods that mask your password
682 (CRAM-MD5, X-OTP - note that NTLM and MSN are not autoprobed for POP3
683 and MSN is only supported for POP3); and only if the server doesn't
684 support any of those will it ship your password en clair. Other values
685 may be used to force various authentication methods
686 (\fBssh\fR suppresses authentication). Any value other than
687 \&\fBpassword\fR, \fBcram-md5\fR, \fBntlm\fR, \fBmsn\fR or \fBotp\fR
688 suppresses fetchmail's normal inquiry for a password. Specify \fBssh\fR
689 when you are using an end-to-end secure connection such as an ssh
690 tunnel; specify \fBgssapi\fR or \fBkerberos_v4\fR if you are using a
691 protocol variant that employs GSSAPI or K4. Choosing KPOP protocol
692 automatically selects Kerberos authentication. This option does not
694 .SS Miscellaneous Options
696 .B \-f <pathname> | \-\-fetchmailrc <pathname>
697 Specify a non-default name for the
699 run control file. The pathname argument must be either "-" (a single
700 dash, meaning to read the configuration from standard input) or a
701 filename. Unless the --version option is also on, a named file
702 argument must have permissions no more open than 0600 (u=rw,g=,o=) or
705 .B \-i <pathname> | \-\-idfile <pathname>
707 Specify an alternate name for the .fetchids file used to save POP3
710 .B \-n | \-\-norewrite
711 (Keyword: no rewrite)
714 edits RFC-822 address headers (To, From, Cc, Bcc, and Reply-To) in
715 fetched mail so that any mail IDs local to the server are expanded to
716 full addresses (@ and the mailserver hostname are appended). This enables
717 replies on the client to get addressed correctly (otherwise your
718 mailer might think they should be addressed to local users on the
719 client machine!). This option disables the rewrite. (This option is
720 provided to pacify people who are paranoid about having an MTA edit
721 mail headers and want to know they can prevent it, but it is generally
722 not a good idea to actually turn off rewrite.)
723 When using ETRN or ODMR, the rewrite option is ineffective.
725 .B \-E <line> | \-\-envelope <line>
726 (Keyword: envelope; Multidrop only)
728 In the configuration file, an enhanced syntax is used:
730 .B envelope [<count>] <line>
732 This option changes the header
734 assumes will carry a copy of the mail's envelope address. Normally
735 this is 'X-Envelope-To' but as this header is not standard, practice
736 varies. See the discussion of multidrop address handling below. As a
737 special case, 'envelope "Received"' enables parsing of sendmail-style
738 Received lines. This is the default, and it should not be necessary
739 unless you have globally disabled Received parsing with 'no envelope'
740 in the \fI.fetchmailrc\fR file.
742 The optional count argument (only available in the configuration file)
743 determines how many header lines of this kind are skipped. A count of 1
744 means: skip the first, take the second. A count of 2 means: skip the
745 first and second, take the third, and so on.
747 .B \-Q <prefix> | \-\-qvirtual <prefix>
748 (Keyword: qvirtual; Multidrop only)
749 The string prefix assigned to this option will be removed from the user
750 name found in the header specified with the \fIenvelope\fR option
751 (\fIbefore\fR doing multidrop name mapping or localdomain checking,
752 if either is applicable). This option is useful if you are using
754 to collect the mail for an entire domain and your ISP (or your mail
755 redirection provider) is using qmail.
756 One of the basic features of qmail is the
760 message header. Whenever qmail delivers a message to a local mailbox
761 it puts the username and hostname of the envelope recipient on this
762 line. The major reason for this is to prevent mail loops. To set up
763 qmail to batch mail for a disconnected site the ISP-mailhost will have
764 normally put that site in its 'Virtualhosts' control file so it will
765 add a prefix to all mail addresses for this site. This results in mail
766 .\" The \&@\& tries to stop HTML converters from making a mailto URL here.
767 sent to 'username\&@\&userhost.userdom.dom.com' having a
768 \&'Delivered-To:' line of the form:
770 Delivered-To: mbox-userstr-username\&@\&userhost.userdom.dom.com
772 The ISP can make the 'mbox-userstr-' prefix anything they choose
773 but a string matching the user host name is likely.
774 By using the option 'envelope Delivered-To:' you can make fetchmail reliably
775 identify the original envelope recipient, but you have to strip the
776 \&'mbox-userstr-' prefix to deliver to the correct user.
777 This is what this option is for.
782 file, interpret any command-line options specified, and dump a
783 configuration report to standard output. The configuration report is
784 a data structure assignment in the language Python. This option
785 is meant to be used with an interactive
793 Removed before version 6.3.0, the required underlying inet6_apps library
794 had been discontinued and is no longer available.
796 .SH USER AUTHENTICATION AND ENCRYPTION
797 All modes except ETRN require authentication of the client to the server.
798 Normal user authentication in
800 is very much like the authentication mechanism of
802 The correct user-id and password depend upon the underlying security
803 system at the mailserver.
805 If the mailserver is a Unix machine on which you have an ordinary user
806 account, your regular login name and password are used with
808 If you use the same login name on both the server and the client machines,
809 you needn't worry about specifying a user-id with the
811 option \-\- the default behavior is to use your login name on the
812 client machine as the user-id on the server machine. If you use a
813 different login name on the server machine, specify that login name
816 option. e.g. if your login name is 'jsmith' on a machine named 'mailgrunt',
821 fetchmail -u jsmith mailgrunt
823 The default behavior of
825 is to prompt you for your mailserver password before the connection is
826 established. This is the safest way to use
828 and ensures that your password will not be compromised. You may also specify
829 your password in your
831 file. This is convenient when using
833 in daemon mode or with scripts.
834 .SS Using netrc files
836 If you do not specify a password, and
838 cannot extract one from your
840 file, it will look for a
842 file in your home directory before requesting one interactively; if an
843 entry matching the mailserver is found in that file, the password will
844 be used. Fetchmail first looks for a match on poll name; if it finds none,
845 it checks for a match on via name. See the
847 man page for details of the syntax of the
849 file. To show a practical example, a .netrc might look like
853 machine hermes.example.org
858 You can repeat this block with different user information if you need to
859 provide more than one password.
861 This feature may allow you to avoid duplicating password
862 information in more than one file.
864 On mailservers that do not provide ordinary user accounts, your user-id and
865 password are usually assigned by the server administrator when you apply for
866 a mailbox on the server. Contact your server administrator if you don't know
867 the correct user-id and password for your mailbox account.
870 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
871 independent authentication using the
873 file on the mailserver side. Under this RPOP variant, a fixed
874 per-user ID equivalent to a password was sent in clear over a link to
875 a reserved port, with the command RPOP rather than PASS to alert the
876 server that it should do special checking. RPOP is supported
879 (you can specify 'protocol RPOP' to have the program send 'RPOP'
880 rather than 'PASS') but its use is strongly discouraged. This
881 facility was vulnerable to spoofing and was withdrawn in RFC1460.
883 RFC1460 introduced APOP authentication. In this variant of POP3,
884 you register an APOP password on your server host (the program
885 to do this with on the server is probably called \fIpopauth\fR(8)). You
886 put the same password in your
890 logs in, it sends a cryptographically secure hash of your password and
891 the server greeting time to the server, which can verify it by
892 checking its authorization database.
893 .SS Alternate authentication forms
895 If your \fIfetchmail\fR was built with Kerberos support and you specify
896 Kerberos authentication (either with --auth or the \fI.fetchmailrc\fR
897 option \fBauthenticate kerberos_v4\fR) it will try to get a Kerberos
898 ticket from the mailserver at the start of each query. Note: if
899 either the pollname or via name is 'hesiod', fetchmail will try to use
900 Hesiod to look up the mailserver.
902 If you use POP3 or IMAP with GSSAPI authentication, \fIfetchmail\fR will
903 expect the server to have RFC1731- or RFC1734-conformant GSSAPI
904 capability, and will use it. Currently this has only been tested over
905 Kerberos V, so you're expected to already have a ticket-granting
906 ticket. You may pass a username different from your principal name
907 using the standard \fB--user\fR command or by the \fI.fetchmailrc\fR
910 If your IMAP daemon returns the PREAUTH response in its greeting line,
911 fetchmail will notice this and skip the normal authentication step.
912 This can be useful, e.g. if you start imapd explicitly using ssh.
913 In this case you can declare the authentication value 'ssh' on that
914 site entry to stop \fI.fetchmail\fR from asking you for a password
917 If you are using POP3, and the server issues a one-time-password
918 challenge conforming to RFC1938, \fIfetchmail\fR will use your
919 password as a pass phrase to generate the required response. This
920 avoids sending secrets over the net unencrypted.
922 Compuserve's RPA authentication (similar to APOP) is supported. If you
923 compile in the support, \fIfetchmail\fR will try to perform an RPA pass-phrase
924 authentication instead of sending over the password en clair if it
925 detects "@compuserve.com" in the hostname.
927 If you are using IMAP, Microsoft's NTLM authentication (used by Microsoft
928 Exchange) is supported. If you compile in the support, \fIfetchmail\fR
929 will try to perform an NTLM authentication (instead of sending over the
930 password en clair) whenever the server returns AUTH=NTLM in its
931 capability response. Specify a user option value that looks like
932 \&'user@domain': the part to the left of the @ will be passed as the
933 username and the part to the right as the NTLM domain.
934 .SS Secure Socket Layers (SSL)
936 You can access SSL encrypted services by specifying the --ssl option.
937 You can also do this using the "ssl" server option in the .fetchmailrc
938 file. With SSL encryption enabled, queries are initiated over a connection
939 after negotiating an SSL session. Some services, such as POP3 and IMAP,
940 have different well known ports defined for the SSL encrypted services.
941 The encrypted ports will be selected automatically when SSL is enabled and
942 no explicit port is specified.
944 When connecting to an SSL encrypted server, the server presents a certificate
945 to the client for validation. The certificate is checked to verify that
946 the common name in the certificate matches the name of the server being
947 contacted and that the effective and expiration dates in the certificate
948 indicate that it is currently valid. If any of these checks fail, a warning
949 message is printed, but the connection continues. The server certificate
950 does not need to be signed by any specific Certifying Authority and may
951 be a "self-signed" certificate.
953 Some SSL encrypted servers may request a client side certificate. A client
954 side public SSL certificate and private SSL key may be specified. If
955 requested by the server, the client certificate is sent to the server for
956 validation. Some servers may require a valid client certificate and may
957 refuse connections if a certificate is not provided or if the certificate
958 is not valid. Some servers may require client side certificates be signed
959 by a recognized Certifying Authority. The format for the key files and
960 the certificate files is that required by the underlying SSL libraries
961 (OpenSSL in the general case).
963 A word of care about the use of SSL: While above mentioned
964 setup with self-signed server certificates retrieved over the wires
965 can protect you from a passive eavesdropper it doesn't help against an
966 active attacker. It's clearly an improvement over sending the
967 passwords in clear but you should be aware that a man-in-the-middle
968 attack is trivially possible (in particular with tools such as dsniff,
969 http://www.monkey.org/~dugsong/dsniff/). Use of an ssh tunnel (see
970 below for some examples) is preferable if you care seriously about the
971 security of your mailbox.
975 also supports authentication to the ESMTP server on the client side
976 according to RFC 2554. You can specify a name/password pair to be
977 used with the keywords 'esmtpname' and 'esmtppassword'; the former
978 defaults to the username of the calling user.
982 .B \-\-daemon <interval>
987 in daemon mode. You must specify a numeric argument which is a
988 polling interval in seconds.
992 puts itself in background and runs forever, querying each specified
993 host and then sleeping for the given polling interval.
999 will, therefore, poll all the hosts described in your
1001 file (except those explicitly excluded with the 'skip' verb) once
1002 every fifteen minutes.
1004 It is possible to set a polling interval
1007 file by saying 'set daemon <interval>', where <interval> is an
1008 integer number of seconds. If you do this, fetchmail will always
1009 start in daemon mode unless you override it with the command-line
1010 option --daemon 0 or -d0.
1012 Only one daemon process is permitted per user; in daemon mode,
1014 makes a per-user lockfile to guarantee this.
1016 Normally, calling fetchmail with a daemon in the background sends a
1017 wake-up signal to the daemon, forcing it to poll mailservers
1018 immediately. (The wake-up signal is SIGHUP if fetchmail is running as
1019 root, SIGUSR1 otherwise.) The wake-up action also clears any 'wedged'
1020 flags indicating that connections have wedged due to failed
1021 authentication or multiple timeouts.
1025 will kill a running daemon process instead of waking it up (if there
1026 is no such process, \fIfetchmail\fP will notify you.
1027 If the \-\-quit option appears last on the command line, \fIfetchmail\fP
1028 will kill the running daemon process and then quit. Otherwise,
1029 \fIfetchmail\fP will first kill a running daemon process and then
1030 continue running with the other options.
1035 .B \-\-logfile <filename>
1036 option (keyword: set logfile) allows you to redirect status messages
1037 emitted while detached into a specified logfile (follow the
1038 option with the logfile name). The logfile is opened for append, so
1039 previous messages aren't deleted. This is primarily useful for
1040 debugging configurations.
1044 option (keyword: set syslog) allows you to redirect status and error
1045 messages emitted to the
1047 system daemon if available.
1048 Messages are logged with an id of \fBfetchmail\fR, the facility \fBLOG_MAIL\fR,
1049 and priorities \fBLOG_ERR\fR, \fBLOG_ALERT\fR or \fBLOG_INFO\fR.
1050 This option is intended for logging status and error messages which
1051 indicate the status of the daemon and the results while fetching mail
1053 Error messages for command line options and parsing the \fI.fetchmailrc\fR
1054 file are still written to stderr, or to the specified log file.
1057 option turns off use of
1059 assuming it's turned on in the
1064 .B \-\-logfile <file>
1071 option suppresses backgrounding and detachment of the
1072 daemon process from its control terminal. This is useful
1073 for debugging or when fetchmail runs as the child of a supervisor
1078 Note that this also causes the logfile option to be
1079 ignored (though perhaps it shouldn't).
1081 Note that while running in daemon mode polling a POP2 or IMAP2bis server,
1082 transient errors (such as DNS failures or sendmail delivery refusals)
1083 may force the fetchall option on for the duration of the next polling
1084 cycle. This is a robustness feature. It means that if a message is
1085 fetched (and thus marked seen by the mailserver) but not delivered
1086 locally due to some transient error, it will be re-fetched during the
1087 next poll cycle. (The IMAP logic doesn't delete messages until
1088 they're delivered, so this problem does not arise.)
1090 If you touch or change the
1092 file while fetchmail is running in daemon mode, this will be detected
1093 at the beginning of the next poll cycle. When a changed
1095 is detected, fetchmail rereads it and restarts from scratch (using
1096 exec(2); no state information is retained in the new instance). Note also
1097 that if you break the
1099 file's syntax, the new instance will softly and silently vanish away
1102 .SH ADMINISTRATIVE OPTIONS
1105 .B \-\-postmaster <name>
1106 option (keyword: set postmaster) specifies the last-resort username to
1107 which multidrop mail is to be forwarded if no matching local recipient
1108 can be found. Normally this is just the user who invoked
1110 If the invoking user is root, then the default of this option is
1111 the user 'postmaster'. Setting postmaster to the empty string causes
1112 such mail to be discarded.
1116 option suppresses the normal action of bouncing errors back to the
1117 sender in an RFC1894-conformant error message. If nobounce is on, the
1118 message will go to the postmaster instead.
1122 option (keyword: set invisible) tries to make fetchmail invisible.
1123 Normally, fetchmail behaves like any other MTA would -- it generates a
1124 Received header into each message describing its place in the chain of
1125 transmission, and tells the MTA it forwards to that the mail came from
1126 the machine fetchmail itself is running on. If the invisible option
1127 is on, the Received header is suppressed and fetchmail tries to spoof
1128 the MTA it forwards to into thinking it came directly from the
1133 option (keyword: set showdots) forces fetchmail to show progress dots
1134 even if the current tty is not stdout (for example logfiles).
1135 Starting with fetchmail version 5.3.0,
1136 progress dots are only shown on stdout by default.
1140 option, you can ask fetchmail to add information to the Received
1141 header on the form "polling {label} account {user}", where {label} is
1142 the account label (from the specified rcfile, normally ~/.fetchmailrc)
1143 and {user} is the username which is used to log on to the mail
1144 server. This header can be used to make filtering email where no
1145 useful header information is available and you want mail from
1146 different accounts sorted into different mailboxes (this could, for
1147 example, occur if you have an account on the same server running a
1148 mailing list, and are subscribed to the list using that account). The
1149 default is not adding any such header. In
1151 this is called 'tracepolls'.
1153 .SH RETRIEVAL FAILURE MODES
1154 The protocols \fIfetchmail\fR uses to talk to mailservers are next to
1155 bulletproof. In normal operation forwarding to port 25, no message is
1156 ever deleted (or even marked for deletion) on the host until the SMTP
1157 listener on the client side has acknowledged to \fIfetchmail\fR that
1158 the message has been either accepted for delivery or rejected due to a
1161 When forwarding to an MDA, however, there is more possibility
1162 of error. Some MDAs are 'safe' and reliably return a nonzero status
1163 on any delivery error, even one due to temporary resource limits.
1166 program is like this; so are most programs designed as mail transport
1171 These programs give back a reliable positive acknowledgement and
1172 can be used with the mda option with no risk of mail loss. Unsafe
1173 MDAs, though, may return 0 even on delivery failure. If this
1174 happens, you will lose mail.
1176 The normal mode of \fIfetchmail\fR is to try to download only 'new'
1177 messages, leaving untouched (and undeleted) messages you have already
1178 read directly on the server (or fetched with a previous \fIfetchmail
1179 --keep\fR). But you may find that messages you've already read on the
1180 server are being fetched (and deleted) even when you don't specify
1181 --all. There are several reasons this can happen.
1183 One could be that you're using POP2. The POP2 protocol includes no
1184 representation of 'new' or 'old' state in messages, so \fIfetchmail\fR
1185 must treat all messages as new all the time. But POP2 is obsolete, so
1188 A potential POP3 problem might be servers that insert messages
1189 in the middle of mailboxes (some VMS implementations of mail are
1190 rumored to do this). The \fIfetchmail\fR code assumes that new
1191 messages are appended to the end of the mailbox; when this is not true
1192 it may treat some old messages as new and vice versa. Using UIDL might
1193 fix this, otherwise, consider switching to IMAP.
1195 Yet another POP3 problem is that if they can't make tempfiles in the
1196 user's home directory, some POP3 servers will hand back an
1197 undocumented response that causes fetchmail to spuriously report "No
1200 The IMAP code uses the presence or absence of the server flag \eSeen
1201 to decide whether or not a message is new. This isn't the right thing
1202 to do, fetchmail should check the UIDVALIDITY and use UID, but it
1203 doesn't do that yet. Under Unix, it counts on your IMAP server to notice
1204 the BSD-style Status flags set by mail user agents and set the \eSeen
1205 flag from them when appropriate. All Unix IMAP servers we know of do
1206 this, though it's not specified by the IMAP RFCs. If you ever trip over
1207 a server that doesn't, the symptom will be that messages you have
1208 already read on your host will look new to the server. In this
1209 (unlikely) case, only messages you fetched with \fIfetchmail --keep\fR
1210 will be both undeleted and marked old.
1212 In ETRN and ODMR modes, \fIfetchmail\fR does not actually retrieve messages;
1213 instead, it asks the server's SMTP listener to start a queue flush
1214 to the client via SMTP. Therefore it sends only undelivered messages.
1217 Many SMTP listeners allow administrators to set up 'spam filters' that
1218 block unsolicited email from specified domains. A MAIL FROM or DATA line that
1219 triggers this feature will elicit an SMTP response which
1220 (unfortunately) varies according to the listener.
1224 return an error code of 571.
1226 According to RFC2821, the correct thing to return in this situation is
1227 550 "Requested action not taken: mailbox unavailable" (the draft adds
1228 "[E.g., mailbox not found, no access, or command rejected for policy
1231 Older versions of the
1233 MTA return 501 "Syntax error in parameters or arguments".
1237 MTA runs 554 as an antispam response.
1240 may reject code with a 500 response (followed by an enhanced status
1241 code that contains more information).
1245 treats as antispam responses and discards
1246 the message can be set with the 'antispam' option. This is one of the
1248 three circumstance under which fetchmail ever discards mail (the others
1249 are the 552 and 553 errors described below, and the suppression of
1250 multidropped messages with a message-ID already seen).
1254 is fetching from an IMAP server, the antispam response will be detected and
1255 the message rejected immediately after the headers have been fetched,
1256 without reading the message body. Thus, you won't pay for downloading
1257 spam message bodies.
1259 By default, the list of antispam responses is empty.
1261 If the \fIspambounce\fR option is on, mail that is spam-blocked
1262 triggers an RFC1892 bounce message informing the originator that we do
1263 not accept mail from it.
1265 .SH SMTP/ESMTP ERROR HANDLING
1266 Besides the spam-blocking described above, fetchmail takes special
1267 actions on the following SMTP/ESMTP error responses
1269 452 (insufficient system storage)
1270 Leave the message in the server mailbox for later retrieval.
1272 552 (message exceeds fixed maximum message size)
1273 Delete the message from the server. Send bounce-mail to the
1276 553 (invalid sending domain)
1277 Delete the message from the server. Don't even try to send
1278 bounce-mail to the originator.
1280 Other errors trigger bounce mail back to the originator.
1282 .SH THE RUN CONTROL FILE
1283 The preferred way to set up fetchmail is to write a
1284 \&\fI.fetchmailrc\fR file in your home directory (you may do this
1285 directly, with a text editor, or indirectly via \fIfetchmailconf\fR).
1286 When there is a conflict between the command-line arguments and the
1287 arguments in this file, the command-line arguments take precedence.
1289 To protect the security of your passwords,
1290 your \fI~/.fetchmailrc\fR may not normally have more than 0600 (u=rw,g=,o=) permissions;
1292 will complain and exit otherwise (this check is suppressed when
1295 You may read the \fI.fetchmailrc\fR file as a list of commands to
1298 is called with no arguments.
1299 .SS Run Control Syntax
1301 Comments begin with a '#' and extend through the end of the line.
1302 Otherwise the file consists of a series of server entries or global
1303 option statements in a free-format, token-oriented syntax.
1305 There are four kinds of tokens: grammar keywords, numbers
1306 (i.e. decimal digit sequences), unquoted strings, and quoted strings.
1307 A quoted string is bounded by double quotes and may contain
1308 whitespace (and quoted digits are treated as a string). An unquoted
1309 string is any whitespace-delimited token that is neither numeric, string
1310 quoted nor contains the special characters ',', ';', ':', or '='.
1312 Any amount of whitespace separates tokens in server entries, but is
1313 otherwise ignored. You may use standard C-style escapes (\en, \et,
1314 \eb, octal, and hex) to embed non-printable characters or string
1315 delimiters in strings.
1317 Each server entry consists of one of the keywords 'poll' or 'skip',
1318 followed by a server name, followed by server options, followed by any
1319 number of user descriptions. Note: the most common cause of syntax
1320 errors is mixing up user and server options.
1322 For backward compatibility, the word 'server' is a synonym for 'poll'.
1324 You can use the noise keywords 'and', 'with',
1325 \&'has', 'wants', and 'options' anywhere in an entry to make
1326 it resemble English. They're ignored, but but can make entries much
1327 easier to read at a glance. The punctuation characters ':', ';' and
1328 \&',' are also ignored.
1331 The 'poll' verb tells fetchmail to query this host when it is run with
1332 no arguments. The 'skip' verb tells
1334 not to poll this host unless it is explicitly named on the command
1335 line. (The 'skip' verb allows you to experiment with test entries
1336 safely, or easily disable entries for hosts that are temporarily down.)
1338 .SS Keyword/Option Summary
1339 Here are the legal options. Keyword suffixes enclosed in
1340 square brackets are optional. Those corresponding to command-line
1341 options are followed by '-' and the appropriate option letter.
1342 If option is only relevant to a single mode of operation, it is noted
1343 as 's' or 'm' for singledrop- or multidrop-mode, respectively.
1345 Here are the legal global options:
1349 Keyword Opt Mode Function
1352 Set a background poll interval in seconds
1354 set postmaster \& \& T{
1355 Give the name of the last-resort mail recipient
1357 set no bouncemail \& \& T{
1358 Direct error mail to postmaster rather than sender
1360 set no spambounce \& \& T{
1363 set logfile \& \& T{
1364 Name of a file to dump error and status messages to
1367 Name of the file to store UID lists in
1370 Do error logging through syslog(3).
1372 set no syslog \& \& T{
1373 Turn off error logging through syslog(3).
1375 set properties \& \& T{
1376 String value is ignored by fetchmail (may be used by extension scripts)
1380 Here are the legal server options:
1384 Keyword Opt Mode Function
1387 Specify DNS name of mailserver, overriding poll name
1390 Specify protocol (case insensitive):
1391 POP2, POP3, IMAP, APOP, KPOP
1393 local[domains] \& m T{
1394 Specify domain(s) to be regarded as local
1397 Specify TCP/IP service port
1399 auth[enticate] \& \& T{
1400 Set authentication type (default 'any')
1403 Server inactivity timeout in seconds (default 300)
1406 Specify envelope-address header name
1409 Disable looking for envelope address
1412 Qmail virtual domain prefix to remove from user name
1415 Specify alternate DNS names of mailserver
1418 specify IP interface(s) that must be up for server poll to take place
1421 Specify IP address to monitor for activity
1424 Specify command through which to make server connections.
1427 Specify command through which to make listener connections.
1430 Enable DNS lookup for multidrop (default)
1433 Disable DNS lookup for multidrop
1436 Do comparison by IP address for multidrop
1438 no checkalias \& m T{
1439 Do comparison by name for multidrop (default)
1442 Force POP3 to use client-side UIDLs
1445 Turn off POP3 use of client-side UIDLs (default)
1448 Only check this site every N poll cycles; N is a numeric argument.
1451 Add poll tracing information to the Received header
1454 Set Kerberos principal (only useful with imap and kerberos)
1457 Set name for RFC2554 authentication to the ESMTP server.
1459 esmtppassword \& \& T{
1460 Set password for RFC2554 authentication to the ESMTP server.
1464 Here are the legal user options:
1468 Keyword Opt Mode Function
1471 Set remote user name
1472 (local user name if name followed by 'here')
1475 Connect local and remote user names
1478 Connect local and remote user names
1481 Specify remote account password
1484 Connect to server over the specified base protocol using SSL encryption
1487 Specify file for client side public SSL certificate
1490 Specify file for client side private SSL key
1493 Force ssl protocol for connection
1496 Specify remote folder to query
1499 Specify smtp host(s) to forward to
1501 fetchdomains \& m T{
1502 Specify domains for which mail should be fetched
1504 smtpaddress -D \& T{
1505 Specify the domain to be put in RCPT TO lines
1508 Specify the user and domain to be put in RCPT TO lines
1511 Specify what SMTP returns are interpreted as spam-policy blocks
1514 Specify MDA for local delivery
1517 Specify BSMTP batch file to append to
1520 Command to be executed before each connection
1522 postconnect \& \& T{
1523 Command to be executed after each connection
1526 Don't delete seen messages from server
1529 Flush all seen messages before querying (DANGEROUS)
1532 Flush all oversized messages before querying
1535 Fetch all messages whether seen or not
1538 Rewrite destination addresses for reply (default)
1541 Strip carriage returns from ends of lines
1544 Force carriage returns at ends of lines
1547 Force BODY=8BITMIME to ESMTP listener
1550 Strip Status and X-Mozilla-Status lines out of incoming mail
1552 dropdelivered \& \& T{
1553 Strip Delivered-To lines out of incoming mail
1556 Convert quoted-printable to 8-bit in MIME messages
1559 Idle waiting for new messages after each poll (IMAP only)
1562 Delete seen messages from server (default)
1565 Don't flush all seen messages before querying (default)
1567 no fetchall \& \& T{
1568 Retrieve only new messages (default)
1571 Don't rewrite headers
1574 Don't strip carriage returns (default)
1577 Don't force carriage returns at EOL (default)
1579 no pass8bits \& \& T{
1580 Don't force BODY=8BITMIME to ESMTP listener (default)
1582 no dropstatus \& \& T{
1583 Don't drop Status headers (default)
1585 no dropdelivered \& \& T{
1586 Don't drop Delivered-To headers (default)
1588 no mimedecode \& \& T{
1589 Don't convert quoted-printable to 8-bit in MIME messages (default)
1592 Don't idle waiting for new messages after each poll (IMAP only)
1595 Set message size limit
1598 Set message size warning interval
1601 Max # messages to forward in single connect
1604 Max # messages to fetch in single connect
1606 fetchsizelimit \& \& T{
1607 Max # message sizes to fetch in single transaction
1610 Use binary search for first unseen message (POP3 only)
1613 Perform an expunge on every #th message (IMAP and POP3 only)
1616 String value is ignored by fetchmail (may be used by extension scripts)
1620 Remember that all user options must \fIfollow\fR all server options.
1622 In the .fetchmailrc file, the 'envelope' string argument may be
1623 preceded by a whitespace-separated number. This number, if specified,
1624 is the number of such headers to skip over (that is, an argument of 1
1625 selects the second header of the given type). This is sometime useful
1626 for ignoring bogus envelope headers created by an ISP's local delivery
1627 agent or internal forwards (through mail inspection systems, for
1629 .SS Keywords Not Corresponding To Option Switches
1631 The 'folder' and 'smtphost' options (unlike their command-line
1632 equivalents) can take a space- or comma-separated list of names
1635 All options correspond to the obvious command-line arguments, except
1636 the following: 'via', 'interval', 'aka', 'is', 'to', 'dns'/'no dns',
1637 \&'checkalias'/'no checkalias', 'password', 'preconnect', 'postconnect',
1638 \&'localdomains', 'stripcr'/'no stripcr', 'forcecr'/'no forcecr',
1639 \&'pass8bits'/'no pass8bits' 'dropstatus/no dropstatus',
1640 \&'dropdelivered/no dropdelivered', 'mimedecode/no mimedecode', 'idle/no
1641 idle', and 'no envelope'.
1643 The 'via' option is for if you want to have more
1644 than one configuration pointing at the same site. If it is present,
1645 the string argument will be taken as the actual DNS name of the
1646 mailserver host to query.
1647 This will override the argument of poll, which can then simply be a
1648 distinct label for the configuration (e.g. what you would give on the
1649 command line to explicitly query this host).
1651 The 'interval' option (which takes a numeric argument) allows you to poll a
1652 server less frequently than the basic poll interval. If you say
1653 \&'interval N' the server this option is attached to will only be
1654 queried every N poll intervals.
1656 The 'is' or 'to' keywords associate the following local (client)
1657 name(s) (or server-name to client-name mappings separated by =) with
1658 the mailserver user name in the entry. If an is/to list has '*' as
1659 its last name, unrecognized names are simply passed through.
1661 A single local name can be used to support redirecting your mail when
1662 your username on the client machine is different from your name on the
1663 mailserver. When there is only a single local name, mail is forwarded
1664 to that local username regardless of the message's Received, To, Cc,
1665 and Bcc headers. In this case
1667 never does DNS lookups.
1669 When there is more than one local name (or name mapping) the
1670 \fIfetchmail\fR code does look at the Received, To, Cc, and Bcc
1671 headers of retrieved mail (this is 'multidrop mode'). It looks for
1672 addresses with hostname parts that match your poll name or your 'via',
1673 \&'aka' or 'localdomains' options, and usually also for hostname parts
1674 which DNS tells it are aliases of the mailserver. See the discussion
1675 of 'dns', 'checkalias', 'localdomains', and 'aka' for details on how
1676 matching addresses are handled.
1678 If \fIfetchmail\fR cannot match any mailserver usernames or
1679 localdomain addresses, the mail will be bounced.
1680 Normally it will be bounced to the sender, but if 'nobounce' is on
1681 it will go to the postmaster (which in turn defaults to being the
1684 The 'dns' option (normally on) controls the way addresses from
1685 multidrop mailboxes are checked. On, it enables logic to check each
1686 host address that doesn't match an 'aka' or 'localdomains' declaration
1687 by looking it up with DNS. When a mailserver username is recognized
1688 attached to a matching hostname part, its local mapping is added to
1689 the list of local recipients.
1691 The 'checkalias' option (normally off) extends the lookups performed
1692 by the 'dns' keyword in multidrop mode, providing a way to cope with
1693 remote MTAs that identify themselves using their canonical name, while
1694 they're polled using an alias.
1695 When such a server is polled, checks to extract the envelope address
1698 reverts to delivery using the To/Cc/Bcc headers (See below
1699 \&'Header vs. Envelope addresses').
1700 Specifying this option instructs
1702 to retrieve all the IP addresses associated with both the poll name
1703 and the name used by the remote MTA and to do a comparison of the IP
1704 addresses. This comes in handy in situations where the remote server
1705 undergoes frequent canonical name changes, that would otherwise
1706 require modifications to the rcfile. 'checkalias' has no effect if
1707 \&'no dns' is specified in the rcfile.
1709 The 'aka' option is for use with multidrop mailboxes. It allows you
1710 to pre-declare a list of DNS aliases for a server. This is an
1711 optimization hack that allows you to trade space for speed. When
1713 while processing a multidrop mailbox, grovels through message headers
1714 looking for names of the mailserver, pre-declaring common ones can
1715 save it from having to do DNS lookups. Note: the names you give
1716 as arguments to 'aka' are matched as suffixes -- if you specify
1717 (say) 'aka netaxs.com', this will match not just a hostname
1718 netaxs.com, but any hostname that ends with '.netaxs.com'; such as
1719 (say) pop3.netaxs.com and mail.netaxs.com.
1721 The 'localdomains' option allows you to declare a list of domains
1722 which fetchmail should consider local. When fetchmail is parsing
1723 address lines in multidrop modes, and a trailing segment of a host
1724 name matches a declared local domain, that address is passed through
1725 to the listener or MDA unaltered (local-name mappings are \fInot\fR
1728 If you are using 'localdomains', you may also need to specify \&'no
1729 envelope', which disables \fIfetchmail\fR's normal attempt to deduce
1730 an envelope address from the Received line or X-Envelope-To header or
1731 whatever header has been previously set by 'envelope'. If you set 'no
1732 envelope' in the defaults entry it is possible to undo that in
1733 individual entries by using 'envelope <string>'. As a special case,
1734 \&'envelope "Received"' restores the default parsing of
1737 The \fBpassword\fR option requires a string argument, which is the password
1738 to be used with the entry's server.
1740 The 'preconnect' keyword allows you to specify a shell command to be
1741 executed just before each time
1743 establishes a mailserver connection. This may be useful if you are
1744 attempting to set up secure POP connections with the aid of
1746 If the command returns a nonzero status, the poll of that mailserver
1749 Similarly, the 'postconnect' keyword similarly allows you to specify a
1750 shell command to be executed just after each time a mailserver
1751 connection is taken down.
1753 The 'forcecr' option controls whether lines terminated by LF only are
1754 given CRLF termination before forwarding. Strictly speaking RFC821
1755 requires this, but few MTAs enforce the requirement it so this option
1756 is normally off (only one such MTA, qmail, is in significant use at
1759 The 'stripcr' option controls whether carriage returns are stripped
1760 out of retrieved mail before it is forwarded. It is normally not
1761 necessary to set this, because it defaults to 'on' (CR stripping
1762 enabled) when there is an MDA declared but 'off' (CR stripping
1763 disabled) when forwarding is via SMTP. If 'stripcr' and 'forcecr' are
1764 both on, 'stripcr' will override.
1766 The 'pass8bits' option exists to cope with Microsoft mail programs that
1767 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
1768 this option off (the default) and such a header present,
1770 declares BODY=7BIT to an ESMTP-capable listener; this causes problems for
1771 messages actually using 8-bit ISO or KOI-8 character sets, which will
1772 be garbled by having the high bits of all characters stripped. If
1773 \&'pass8bits' is on,
1775 is forced to declare BODY=8BITMIME to any ESMTP-capable listener. If
1776 the listener is 8-bit-clean (as all the major ones now are) the right
1777 thing will probably result.
1779 The 'dropstatus' option controls whether nonempty Status and
1780 X-Mozilla-Status lines are retained in fetched mail (the default) or
1781 discarded. Retaining them allows your MUA to see what messages (if
1782 any) were marked seen on the server. On the other hand, it can
1783 confuse some new-mail notifiers, which assume that anything with a
1784 Status line in it has been seen. (Note: the empty Status lines
1785 inserted by some buggy POP servers are unconditionally discarded.)
1787 The 'dropdelivered' option controls whether Delivered-To headers will
1788 be kept in fetched mail (the default) or discarded. These headers are
1789 added by Qmail and Postfix mailservers in order to avoid mail loops but
1790 may get in your way if you try to "mirror" a mailserver within the same
1791 domain. Use with caution.
1793 The 'mimedecode' option controls whether MIME messages using the
1794 quoted-printable encoding are automatically converted into pure 8-bit
1795 data. If you are delivering mail to an ESMTP-capable, 8-bit-clean
1796 listener (that includes all of the major MTAs like sendmail), then
1797 this will automatically convert quoted-printable message headers and
1798 data into 8-bit data, making it easier to understand when reading
1799 mail. If your e-mail programs know how to deal with MIME messages,
1800 then this option is not needed. The mimedecode option is off by
1801 default, because doing RFC2047 conversion on headers throws away
1802 character-set information and can lead to bad results if the encoding
1803 of the headers differs from the body encoding.
1805 The 'idle' option is intended to be used with IMAP servers supporting
1806 the RFC2177 IDLE command extension, but does not strictly require it.
1807 If it is enabled, and fetchmail detects that IDLE is supported, an
1808 IDLE will be issued at the end of each poll. This will tell the IMAP
1809 server to hold the connection open and notify the client when new mail
1810 is available. If IDLE is not supported, fetchmail will simulate it by
1811 periodically issuing NOOP. If you need to poll a link frequently, IDLE
1812 can save bandwidth by eliminating TCP/IP connects and LOGIN/LOGOUT
1813 sequences. On the other hand, an IDLE connection will eat almost all
1814 of your fetchmail's time, because it will never drop the connection
1815 and allow other pools to occur unless the server times out the IDLE.
1816 It also doesn't work with multiple folders; only the first folder will
1820 The 'properties' option is an extension mechanism. It takes a string
1821 argument, which is ignored by fetchmail itself. The string argument may be
1822 used to store configuration information for scripts which require it.
1823 In particular, the output of '--configdump' option will make properties
1824 associated with a user entry readily available to a Python script.
1826 .SS Miscellaneous Run Control Options
1827 The words 'here' and 'there' have useful English-like
1828 significance. Normally 'user eric is esr' would mean that
1829 mail for the remote user 'eric' is to be delivered to 'esr',
1830 but you can make this clearer by saying 'user eric there is esr here',
1831 or reverse it by saying 'user esr here is eric there'
1833 Legal protocol identifiers for use with the 'protocol' keyword are:
1846 Legal authentication types are 'any', 'password', 'kerberos',
1847 \&'kerberos_v4', 'kerberos_v5' and 'gssapi', 'cram-md5', 'otp', 'msn'
1848 (only for POP3), 'ntlm', 'ssh'. The 'password' type specifies
1849 authentication by normal transmission of a password (the password may be
1850 plain text or subject to protocol-specific encryption as in APOP);
1851 \&'kerberos' tells \fIfetchmail\fR to try to get a Kerberos ticket at the
1852 start of each query instead, and send an arbitrary string as the
1853 password; and 'gssapi' tells fetchmail to use GSSAPI authentication.
1854 See the description of the 'auth' keyword for more.
1856 Specifying 'kpop' sets POP3 protocol over port 1109 with Kerberos V4
1857 authentication. These defaults may be overridden by later options.
1859 There are currently four global option statements; 'set logfile'
1860 followed by a string sets the same global specified by --logfile. A
1861 command-line --logfile option will override this. Also, 'set daemon'
1862 sets the poll interval as --daemon does. This can be overridden by a
1863 command-line --daemon option; in particular --daemon 0 can be used to
1864 force foreground operation. The 'set postmaster' statement sets the
1865 address to which multidrop mail defaults if there are no local
1866 matches. Finally, 'set syslog' sends log messages to syslogd(8).
1868 .SH INTERACTION WITH RFC 822
1869 When trying to determine the originating address of a message,
1870 fetchmail looks through headers in the following order:
1874 Resent-Sender: (ignored if it doesn't contain an @ or !)
1875 Sender: (ignored if it doesn't contain an @ or !)
1882 The originating address is used for logging, and to set the MAIL FROM
1883 address when forwarding to SMTP. This order is intended to cope
1884 gracefully with receiving mailing list messages in multidrop mode. The
1885 intent is that if a local address doesn't exist, the bounce message
1886 won't be returned blindly to the author or to the list itself, but
1887 rather to the list manager (which is less annoying).
1889 In multidrop mode, destination headers are processed as follows:
1890 First, fetchmail looks for the Received: header (or whichever one is
1891 specified by the 'envelope' option) to determine the local
1892 recipient address. If the mail is addressed to more than one recipient,
1893 the Received line won't contain any information regarding recipient addresses.
1895 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
1896 lines. If they exist, they should contain the final recipients and
1897 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent-*
1898 lines don't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
1899 looked for. (The presence of a Resent-To: is taken to imply that the
1900 person referred by the To: address has already received the original
1903 .SH CONFIGURATION EXAMPLES
1904 Note that although there are password declarations in a good many
1905 of the examples below, this is mainly for illustrative purposes.
1906 We recommend stashing account/password pairs in your $HOME/.netrc
1907 file, where they can be used not just by fetchmail but by ftp(1) and
1913 poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD
1919 poll pop.provider.net protocol pop3 username "jsmith" password "secret1"
1922 Or, using some abbreviations:
1925 poll pop.provider.net proto pop3 user "jsmith" password "secret1"
1928 Multiple servers may be listed:
1931 poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
1932 poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"
1935 Here's a version of those two with more whitespace and some noise words:
1938 poll pop.provider.net proto pop3
1939 user "jsmith", with password secret1, is "jsmith" here;
1940 poll other.provider.net proto pop2:
1941 user "John.Smith", with password "My^Hat", is "John.Smith" here;
1944 This version is much easier to read and doesn't cost significantly
1945 more (parsing is done only once, at startup time).
1948 If you need to include whitespace in a parameter string, enclose the
1949 string in double quotes. Thus:
1952 poll mail.provider.net with proto pop3:
1953 user "jsmith" there has password "u can't krak this"
1954 is jws here and wants mda "/bin/mail"
1957 You may have an initial server description headed by the keyword
1958 \&'defaults' instead of 'poll' followed by a name. Such a record
1959 is interpreted as defaults for all queries to use. It may be overwritten
1960 by individual server descriptions. So, you could write:
1965 poll pop.provider.net
1967 poll mail.provider.net
1968 user "jjsmith" there has password "secret2"
1971 It's possible to specify more than one user per server (this is only
1972 likely to be useful when running fetchmail in daemon mode as root).
1973 The 'user' keyword leads off a user description, and every user specification
1974 in a multi-user entry must include it. Here's an example:
1977 poll pop.provider.net proto pop3 port 3111
1978 user "jsmith" with pass "secret1" is "smith" here
1979 user jones with pass "secret2" is "jjones" here keep
1982 This associates the local username 'smith' with the pop.provider.net
1983 username 'jsmith' and the local username 'jjones' with the
1984 pop.provider.net username 'jones'. Mail for 'jones' is kept on the
1985 server after download.
1987 Here's what a simple retrieval configuration for a multi-drop mailbox
1991 poll pop.provider.net:
1992 user maildrop with pass secret1 to golux 'hurkle'='happy' snark here
1995 This says that the mailbox of account 'maildrop' on the server is a
1996 multi-drop box, and that messages in it should be parsed for the
1997 server user names 'golux', 'hurkle', and 'snark'. It further
1998 specifies that 'golux' and 'snark' have the same name on the
1999 client as on the server, but mail for server user 'hurkle' should be
2000 delivered to client user 'happy'.
2002 Here's an example of another kind of multidrop connection:
2005 poll pop.provider.net localdomains loonytoons.org toons.org:
2006 user maildrop with pass secret1 to * here
2009 This also says that the mailbox of account 'maildrop' on the server is
2010 a multi-drop box. It tells fetchmail that any address in the
2011 loonytoons.org or toons.org domains (including sub-domain addresses like
2012 \&'joe@daffy.loonytoons.org') should be passed through to the local SMTP
2013 listener without modification. Be careful of mail loops if you do this!
2015 Here's an example configuration using ssh and the plugin option. The
2016 queries are made directly on the stdin and stdout of imapd via ssh.
2017 Note that in this setup, IMAP authentication can be skipped.
2020 poll mailhost.net with proto imap:
2021 plugin "ssh %h /usr/sbin/imapd" auth ssh;
2022 user esr is esr here
2025 .SH THE USE AND ABUSE OF MULTIDROP MAILBOXES
2026 Use the multiple-local-recipients feature with caution -- it can bite.
2027 All multidrop features are ineffective in ETRN and ODMR modes.
2029 Also, note that in multidrop mode duplicate mails are suppressed. A
2030 piece of mail is considered duplicate if it has the same message-ID as
2031 the message immediately preceding and more than one addressee. Such
2032 runs of messages may be generated when copies of a message addressed
2033 to multiple users are delivered to a multidrop box.
2035 .SS Header vs. Envelope addresses
2036 The fundamental problem is that by having your mailserver toss several
2037 peoples' mail in a single maildrop box, you may have thrown away
2038 potentially vital information about who each piece of mail was
2039 actually addressed to (the 'envelope address', as opposed to the
2040 header addresses in the RFC822 To/Cc headers - the Bcc is not available
2041 at the receiving end). This 'envelope address' is the address you need
2042 in order to reroute mail properly.
2046 can deduce the envelope address. If the mailserver MTA is
2048 and the item of mail had just one recipient, the MTA will have written
2049 a 'by/for' clause that gives the envelope addressee into its Received
2050 header. But this doesn't work reliably for other MTAs, nor if there is
2051 more than one recipient. By default, \fIfetchmail\fR looks for
2052 envelope addresses in these lines; you can restore this default with
2053 -E "Received" or \&'envelope Received'.
2055 .B As a better alternative,
2056 some SMTP listeners and/or mail servers insert a header
2057 in each message containing a copy of the envelope addresses. This
2058 header (when it exists) is often 'X-Original-To', 'Delivered-To' or
2059 'X-Envelope-To'. Fetchmail's assumption about this can be changed with
2060 the -E or 'envelope' option. Note that writing an envelope header of
2061 this kind exposes the names of recipients (including blind-copy
2062 recipients) to all receivers of the messages, so the upstream must store
2063 one copy of the message per recipient to avoid becoming a privacy problem.
2065 Postfix, since version 2.0, writes an X-Original-To: header which
2066 contains a copy of the envelope as it was received.
2068 Qmail and Postfix generally write a 'Delivered-To' header upon
2069 delivering the message to the mail spool and use it to avoid mail loops.
2070 Qmail virtual domains however will prefix the user name with a string
2071 that normally matches the user's domain. To remove this prefix you can
2072 use the -Q or 'qvirtual' option.
2074 Sometimes, unfortunately, neither of these methods works. That is the
2075 point when you should contact your ISP and ask them to provide such an
2076 envelope header, and you should not use multidrop in this situation.
2077 When they all fail, fetchmail must fall back on the contents of To/Cc
2078 headers (Bcc headers are not available - see below) to try to determine
2079 recipient addressees -- and these are unreliable.
2080 In particular, mailing-list software often ships mail with only
2081 the list broadcast address in the To header.
2083 .B Note that a future version of fetchmail may remove To/Cc parsing!
2087 cannot deduce a recipient address that is local, and the intended
2088 recipient address was anyone other than fetchmail's invoking user,
2089 .B mail will get lost.
2090 This is what makes the multidrop feature risky without proper envelope
2093 A related problem is that when you blind-copy a mail message, the Bcc
2094 information is carried \fIonly\fR as envelope address (it's removed from
2095 the headers by the sending mail server, so fetchmail can see it only if
2096 there is an X-Envelope-To header). Thus, blind-copying to someone who
2097 gets mail over a fetchmail multidrop link will fail unless the the
2098 mailserver host routinely writes X-Envelope-To or an equivalent header
2099 into messages in your maildrop.
2101 \fBIn conclusion, mailing lists and Bcc'd mail can only work if the
2102 server you're fetching from (1) stores one copy of the message per
2103 recipient in \fBIyour\fP domain and (2) records the envelope
2104 information in a special header (X-Original-To, Delivered-To,
2107 .SS Good Ways To Use Multidrop Mailboxes
2108 Multiple local names can be used to administer a mailing list from the
2109 client side of a \fIfetchmail\fR collection. Suppose your name is
2110 \&'esr', and you want to both pick up your own mail and maintain a mailing
2111 list called (say) "fetchmail-friends", and you want to keep the alias
2112 list on your client machine.
2114 On your server, you can alias \&'fetchmail-friends' to 'esr'; then, in
2115 your \fI.fetchmailrc\fR, declare \&'to esr fetchmail-friends here'.
2116 Then, when mail including 'fetchmail-friends' as a local address
2117 gets fetched, the list name will be appended to the list of
2118 recipients your SMTP listener sees. Therefore it will undergo alias
2119 expansion locally. Be sure to include 'esr' in the local alias
2120 expansion of fetchmail-friends, or you'll never see mail sent only to
2121 the list. Also be sure that your listener has the "me-too" option set
2122 (sendmail's -oXm command-line option or OXm declaration) so your name
2123 isn't removed from alias expansions in messages you send.
2125 This trick is not without its problems, however. You'll begin to see
2126 this when a message comes in that is addressed only to a mailing list
2127 you do \fInot\fR have declared as a local name. Each such message
2128 will feature an 'X-Fetchmail-Warning' header which is generated
2129 because fetchmail cannot find a valid local name in the recipient
2130 addresses. Such messages default (as was described above) to being
2131 sent to the local user running
2133 but the program has no way to know that that's actually the right thing.
2135 .SS Bad Ways To Abuse Multidrop Mailboxes
2136 Multidrop mailboxes and
2138 serving multiple users in daemon mode do not mix. The problem, again, is
2139 mail from mailing lists, which typically does not have an individual
2140 recipient address on it. Unless
2142 can deduce an envelope address, such mail will only go to the account
2143 running fetchmail (probably root). Also, blind-copied users are very
2144 likely never to see their mail at all.
2146 If you're tempted to use
2148 to retrieve mail for multiple users from a single mail drop via POP or
2149 IMAP, think again (and reread the section on header and envelope
2150 addresses above). It would be smarter to just let the mail sit in the
2151 mailserver's queue and use fetchmail's ETRN or ODMR modes to trigger
2152 SMTP sends periodically (of course, this means you have to poll more
2153 frequently than the mailserver's expiry period). If you can't arrange
2154 this, try setting up a UUCP feed.
2156 If you absolutely \fImust\fR use multidrop for this purpose, make sure
2157 your mailserver writes an envelope-address header that fetchmail can
2158 see. Otherwise you \fIwill\fR lose mail and it \fIwill\fR come back
2161 .SS Speeding Up Multidrop Checking
2162 Normally, when multiple users are declared
2164 extracts recipient addresses as described above and checks each host
2165 part with DNS to see if it's an alias of the mailserver. If so, the
2166 name mappings described in the "to ... here" declaration are done and
2167 the mail locally delivered.
2169 This is a convenient but also slow method. To speed
2170 it up, pre-declare mailserver aliases with 'aka'; these are checked
2171 before DNS lookups are done. If you're certain your aka list contains
2173 DNS aliases of the mailserver (and all MX names pointing at it - note
2174 this may change in a future version)
2175 you can declare 'no dns' to suppress DNS lookups entirely and
2176 \fIonly\fR match against the aka list.
2179 To facilitate the use of
2181 in shell scripts, an exit code is returned to give an indication
2182 of what occurred during a given connection.
2184 The exit codes returned by
2188 One or more messages were successfully retrieved (or, if the -c option
2189 was selected, were found waiting but not retrieved).
2191 There was no mail awaiting retrieval. (There may have been old mail still
2192 on the server but not selected for retrieval.)
2194 An error was encountered when attempting to open a socket to retrieve
2195 mail. If you don't know what a socket is, don't worry about it --
2196 just treat this as an 'unrecoverable error'. This error can also be
2197 because a protocol fetchmail wants to use is not listed in /etc/services.
2199 The user authentication step failed. This usually means that a bad
2200 user-id, password, or APOP id was specified. Or it may mean that you
2201 tried to run fetchmail under circumstances where it did not have
2202 standard input attached to a terminal and could not prompt for a
2205 Some sort of fatal protocol error was detected.
2207 There was a syntax error in the arguments to
2210 The run control file had bad permissions.
2212 There was an error condition reported by the server. Can also
2215 timed out while waiting for the server.
2217 Client-side exclusion error. This means
2219 either found another copy of itself already running, or failed in such
2220 a way that it isn't sure whether another copy is running.
2222 The user authentication step failed because the server responded "lock
2223 busy". Try again after a brief pause! This error is not implemented
2224 for all protocols, nor for all servers. If not implemented for your
2225 server, "3" will be returned instead, see above. May be returned when
2226 talking to qpopper or other servers that can respond with "lock busy"
2227 or some similar text containing the word "lock".
2231 run failed while trying to do an SMTP port open or transaction.
2233 Fatal DNS error. Fetchmail encountered an error while performing
2234 a DNS lookup at startup and could not proceed.
2236 BSMTP batch file could not be opened.
2238 Poll terminated by a fetch limit (see the --fetchlimit option).
2240 Server busy indication.
2242 Server timed out during an IMAP IDLE.
2244 Internal error. You should see a message on standard error with
2249 queries more than one host, return status is 0 if \fIany\fR query
2250 successfully retrieved mail. Otherwise the returned error status is
2251 that of the last host queried.
2256 default run control file
2259 default location of file associating hosts with last message IDs seen
2260 (used only with newer RFC1939-compliant POP3 servers supporting the
2264 lock file to help prevent concurrent runs (non-root mode).
2267 your FTP run control file, which (if present) will be searched for
2268 passwords as a last resort before prompting for one interactively.
2270 /var/run/fetchmail.pid
2271 lock file to help prevent concurrent runs (root mode, Linux systems).
2274 lock file to help prevent concurrent runs (root mode, systems without /var/run).
2277 If the FETCHMAILUSER variable is set, it is used as the name of the
2278 calling user (default local name) for purposes such as mailing error
2279 notifications. Otherwise, if either the LOGNAME or USER variable is
2280 correctly set (e.g. the corresponding UID matches the session user ID)
2281 then that name is used as the default local name. Otherwise
2282 \fBgetpwuid\fR(3) must be able to retrieve a password entry for the
2283 session ID (this elaborate logic is designed to handle the case of
2284 multiple names per userid gracefully).
2286 If the environment variable FETCHMAILHOME is set to a valid and
2287 existing directory name, the .fetchmailrc and .fetchids and
2288 \&.fetchmail.pid files are put there instead of in the invoking user's
2289 home directory (and lose the leading dots on their names). The
2290 \&.netrc file is looked for in the the invoking user's home directory
2291 regardless of FETCHMAILHOME's setting.
2293 If the HOME_ETC variable is set, file $HOME_ETC/.fetchmailrc is used
2294 instead of ~/.fetchmailrc.
2299 daemon is running as root, SIGHUP wakes it up from its sleep phase and
2300 forces a poll of all non-skipped servers (this is in accordance with
2301 the usual conventions for system daemons).
2305 is running in daemon mode as non-root, use SIGUSR1 to wake it (this is
2306 so SIGHUP due to logout can retain the default action of killing it).
2310 in foreground while a background fetchmail is running will do
2311 whichever of these is appropriate to wake it up.
2313 .SH BUGS AND KNOWN PROBLEMS
2315 The assumptions that the DNS and in particular the checkalias options
2316 make are not often sustainable. For instance, it has become uncommon for
2317 an MX server to be a POP3 or IMAP server at the same time. Therefore the
2318 MX lookups may go away in a future release.
2320 The mda and plugin options interact badly. In order to collect error
2321 status from the MDA, fetchmail has to change its normal signal
2322 handling so that dead plugin processes don't get reaped until the end
2323 of the poll cycle. This can cause resource starvation if too many
2324 zombies accumulate. So either don't deliver to a MDA using plugins or
2325 risk being overrun by an army of undead.
2327 The --interface option does not support IPv6 and it is doubtful if it
2328 ever will, since there is no portable way to query interface IPv6
2331 The RFC822 address parser used in multidrop mode chokes on some
2332 @-addresses that are technically legal but bizarre. Strange uses of
2333 quoting and embedded comments are likely to confuse it.
2335 In a message with multiple envelope headers, only the last one
2336 processed will be visible to fetchmail. To get around this, use a
2337 mailserver-side filter that consolidates the contents of all envelope
2338 headers into a single one (procmail, mailagent, or maildrop can be
2339 programmed to do this fairly easily).
2341 Use of some of these protocols requires that the program send
2342 unencrypted passwords over the TCP/IP connection to the mailserver.
2343 This creates a risk that name/password pairs might be snaffled with a
2344 packet sniffer or more sophisticated monitoring software. Under Linux
2345 and FreeBSD, the --interface option can be used to restrict polling to
2346 availability of a specific interface device with a specific local or
2347 remote IP address, but snooping is still possible if (a) either host
2348 has a network device that can be opened in promiscuous mode, or (b)
2349 the intervening network link can be tapped. We recommend the use of
2351 tunnelling to not only shroud your passwords but encrypt the entire
2354 Use of the %F or %T escapes in an mda option could open a security
2355 hole, because they pass text manipulable by an attacker to a shell
2356 command. Potential shell characters are replaced by '_' before
2357 execution. The hole is further reduced by the fact that fetchmail
2358 temporarily discards any suid privileges it may have while running the
2359 MDA. For maximum safety, however, don't use an mda command containing
2360 %F or %T when fetchmail is run from the root account itself.
2362 Fetchmail's method of sending bouncemail and spam bounces requires that
2363 port 25 of localhost be available for sending mail via SMTP.
2367 while a background instance is running and break the syntax, the
2368 background instance will die silently. Unfortunately, it can't
2369 die noisily because we don't yet know whether syslog should be enabled.
2370 On some systems, fetchmail dies quietly even if there is no syntax
2371 error; this seems to have something to do with buggy terminal ioctl
2374 The -f - option (reading a configuration from stdin) is incompatible
2375 with the plugin option.
2377 The 'principal' option only handles Kerberos IV, not V.
2379 Send comments, bug reports, gripes, and the like to the
2380 fetchmail-devel list <fetchmail-devel@lists.berlios.de>. An HTML FAQ is
2381 available at the fetchmail home page; surf to
2382 http://fetchmail.berlios.de/ or do a WWW search for pages with
2383 \&'fetchmail' in their titles.
2386 Eric S. Raymond <esr@snark.thyrsus.com>. Too many other people to
2387 name here have contributed code and patches.
2388 This program is descended from and replaces
2390 by Carl Harris <ceharris@mal.com>; the internals have become quite different,
2391 but some of its interface design is directly traceable to that
2394 This manual page has been improved by R.\ Hannes Beinert.
2396 Fetchmail is currently maintained by Matthias Andree and Rob Funk.
2399 mutt(1), elm(1), mail(1), sendmail(8), popd(8), imapd(8), netrc(5)
2400 .SH APPLICABLE STANDARDS
2403 RFC 821, RFC2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC 1985,
2407 RFC 822, RFC2822, RFC 1123, RFC 1892, RFC 1894.
2413 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC1734, RFC 1939, RFC 1957,
2417 RFC 1460, RFC 1725, RFC 1939.
2426 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC 2177,
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