1fetchmail(1) fetchmail reference manual fetchmail(1)
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6 fetchmail - fetch mail from a POP, IMAP, ETRN, or ODMR-capable server
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10 fetchmail [option...] [mailserver...]
11 fetchmailconf
12
15 fetchmail is a mail-retrieval and forwarding utility; it fetches mail
16 from remote mailservers and forwards it to your local (client)
17 machine's delivery system. You can then handle the retrieved mail
18 using normal mail user agents such as mutt(1), elm(1) or Mail(1). The
19 fetchmail utility can be run in a daemon mode to repeatedly poll one or
20 more systems at a specified interval.
21 The fetchmail program can gather mail from servers supporting any of
23 the common mail-retrieval protocols: POP2 (legacy, to be removed from
24 future release), POP3, IMAP2bis, IMAP4, and IMAP4rev1. It can also use
25 the ESMTP ETRN extension and ODMR. (The RFCs describing all these pro‐
26 tocols are listed at the end of this manual page.)
27 While fetchmail is primarily intended to be used over on-demand TCP/IP
29 links (such as SLIP or PPP connections), it may also be useful as a
30 message transfer agent for sites which refuse for security reasons to
31 permit (sender-initiated) SMTP transactions with sendmail.
32 If fetchmail is used with a POP or an IMAP server, it has two fundamen‐
34 tal modes of operation for each user account from which it retrieves
35 mail: singledrop- and multidrop-mode. In singledrop-mode, fetchmail
36 assumes that all messages in the user's account are intended for a sin‐
37 gle recipient. An individual mail message will not be inspected for
38 recipient information, rather, the identity of the recipient will
39 either default to the local user currently executing fetchmail, or else
40 will need to be explicitly specified in the configuration file. Sin‐
41 gledrop-mode is used when the fetchmailrc configuration contains at
42 most a single local user specification for a given server account.
43 With multidrop-mode, fetchmail is not able to assume that there is only
45 a single recipient, but rather that the mail server account actually
46 contains mail intended for any number of different recipients. There‐
47 fore, fetchmail must attempt to deduce the proper "envelope recipient"
48 from the mail headers of each message. In this mode of operation,
49 fetchmail almost resembles an MTA, however it is important to note that
50 neither the POP nor IMAP protocols were intended for use in this fash‐
51 ion, and hence envelope information is often not directly available.
52 Instead, fetchmail must resort to a process of informed guess-work in
53 an attempt to discover the true envelope recipient of a message, unless
54 the ISP stores the envelope information in some header (not all do).
55 Even if this information is present in the headers, the process can be
56 error-prone and is dependent upon the specific mail server used for
57 mail retrieval. Multidrop-mode is used when more than one local user
58 is specified for a particular server account in the configuration file.
59 Note that the forgoing discussion of singledrop- and multidrop-modes
60 does not apply to the ESMTP ETRN or ODMR retrieval methods, since they
61 are based upon the SMTP protocol which specifically provides the enve‐
62 lope recipient to fetchmail.
63 As each message is retrieved, fetchmail normally delivers it via SMTP
65 to port 25 on the machine it is running on (localhost), just as though
66 it were being passed in over a normal TCP/IP link. fetchmail provides
67 the SMTP server with an envelope recipient derived in the manner
68 described previously. The mail will then be delivered locally via your
69 system's MDA (Mail Delivery Agent, usually sendmail(8) but your system
70 may use a different one such as smail, mmdf, exim, postfix, or qmail).
71 All the delivery-control mechanisms (such as .forward files) normally
72 available through your system MDA and local delivery agents will there‐
73 fore work automatically.
74 If no port 25 listener is available, but your fetchmail configuration
76 was told about a reliable local MDA, it will use that MDA for local
77 delivery instead.
78 If the program fetchmailconf is available, it will assist you in set‐
80 ting up and editing a fetchmailrc configuration. It runs under the X
81 window system and requires that the language Python and the Tk toolkit
82 be present on your system. If you are first setting up fetchmail for
83 single-user mode, it is recommended that you use Novice mode. Expert
84 mode provides complete control of fetchmail configuration, including
85 the multidrop features. In either case, the 'Autoprobe' button will
86 tell you the most capable protocol a given mailserver supports, and
87 warn you of potential problems with that server.
88
91 The behavior of fetchmail is controlled by command-line options and a
92 run control file, ~/.fetchmailrc, the syntax of which we describe in a
93 later section (this file is what the fetchmailconf program edits).
94 Command-line options override ~/.fetchmailrc declarations.
95 Each server name that you specify following the options on the command
97 line will be queried. If you don't specify any servers on the command
98 line, each 'poll' entry in your ~/.fetchmailrc file will be queried.
99 To facilitate the use of fetchmail in scripts and pipelines, it returns
101 an appropriate exit code upon termination -- see EXIT CODES below.
102 The following options modify the behavior of fetchmail. It is seldom
104 necessary to specify any of these once you have a working .fetchmailrc
105 file set up.
106 Almost all options have a corresponding keyword which can be used to
108 declare them in a .fetchmailrc file.
109 Some special options are not covered here, but are documented instead
111 in sections on AUTHENTICATION and DAEMON MODE which follow.
112 General Options
114 -V | --version
115 Displays the version information for your copy of fetchmail. No
116 mail fetch is performed. Instead, for each server specified,
117 all the option information that would be computed if fetchmail
118 were connecting to that server is displayed. Any non-printables
119 in passwords or other string names are shown as backslashed C-
120 like escape sequences. This option is useful for verifying that
121 your options are set the way you want them.
122 -c | --check
124 Return a status code to indicate whether there is mail waiting,
125 without actually fetching or deleting mail (see EXIT CODES
126 below). This option turns off daemon mode (in which it would be
127 useless). It doesn't play well with queries to multiple sites,
128 and doesn't work with ETRN or ODMR. It will return a false pos‐
129 itive if you leave read but undeleted mail in your server mail‐
130 box and your fetch protocol can't tell kept messages from new
131 ones. This means it will work with IMAP, not work with POP2,
132 and may occasionally flake out under POP3.
133 -s | --silent
135 Silent mode. Suppresses all progress/status messages that are
136 normally echoed to standard output during a fetch (but does not
137 suppress actual error messages). The --verbose option overrides
138 this.
139 -v | --verbose
141 Verbose mode. All control messages passed between fetchmail and
142 the mailserver are echoed to stdout. Overrides --silent. Dou‐
143 bling this option (-v -v) causes extra diagnostic information to
144 be printed.
145 Disposal Options
147 -a | --all | (since v6.3.3) --fetchall
148 (Keyword: fetchall, since v3.0) Retrieve both old (seen) and new
149 messages from the mailserver. The default is to fetch only mes‐
150 sages the server has not marked seen. Under POP3, this option
151 also forces the use of RETR rather than TOP. Note that POP2
152 retrieval behaves as though --all is always on (see RETRIEVAL
153 FAILURE MODES below) and this option does not work with ETRN or
154 ODMR. While the -a and --all command-line and fetchall rcfile
155 options have been supported for a long time, the --fetchall com‐
156 mand-line option was added in v6.3.3.
157 -k | --keep
159 (Keyword: keep) Keep retrieved messages on the remote
160 mailserver. Normally, messages are deleted from the folder on
161 the mailserver after they have been retrieved. Specifying the
162 keep option causes retrieved messages to remain in your folder
163 on the mailserver. This option does not work with ETRN or ODMR.
164 If used with POP3, it is recommended to also specify the --uidl
165 option or uidl keyword.
166 -K | --nokeep
168 (Keyword: nokeep) Delete retrieved messages from the remote
169 mailserver. This option forces retrieved mail to be deleted.
170 It may be useful if you have specified a default of keep in your
171 .fetchmailrc. This option is forced on with ETRN and ODMR.
172 -F | --flush
174 POP3/IMAP only. This is a dangerous option and can cause mail
175 loss when used improperly. It deletes old (seen) messages from
176 the mailserver before retrieving new messages. Warning: This
177 can cause mail loss if you check your mail with other clients
178 than fetchmail, and cause fetchmail to delete a message it had
179 never fetched before. It can also cause mail loss if the mail
180 server marks the message seen after retrieval (IMAP2 servers).
181 You should probably not use this option in your configuration
182 file. If you use it with POP3, you must use the 'uidl' option.
183 What you probably want is the default setting: if you don't
184 specify '-k', then fetchmail will automatically delete messages
185 after successful delivery.
186 --limitflush
188 POP3/IMAP only, since version 6.3.0. Delete oversized messages
189 from the mailserver before retrieving new messages. The size
190 limit should be separately specified with the --limit option.
191 This option does not work with ETRN or ODMR.
192 Protocol and Query Options
194 -p <proto> | --proto <proto> | --protocol <proto>
195 (Keyword: proto[col]) Specify the protocol to use when communi‐
196 cating with the remote mailserver. If no protocol is specified,
197 the default is AUTO. proto may be one of the following:
198 AUTO Tries IMAP, POP3, and POP2 (skipping any of these for
200 which support has not been compiled in).
201 POP2 Post Office Protocol 2 (legacy, to be removed from future
203 release)
204 POP3 Post Office Protocol 3
206 APOP Use POP3 with old-fashioned MD5-challenge authentication.
208 RPOP Use POP3 with RPOP authentication.
210 KPOP Use POP3 with Kerberos V4 authentication on port 1109.
212 SDPS Use POP3 with Demon Internet's SDPS extensions.
214 IMAP IMAP2bis, IMAP4, or IMAP4rev1 (fetchmail automatically
216 detects their capabilities).
217 ETRN Use the ESMTP ETRN option.
219 ODMR Use the the On-Demand Mail Relay ESMTP profile.
221 All these alternatives work in basically the same way (communicating
223 with standard server daemons to fetch mail already delivered to a mail‐
224 box on the server) except ETRN and ODMR. The ETRN mode allows you to
225 ask a compliant ESMTP server (such as BSD sendmail at release 8.8.0 or
226 higher) to immediately open a sender-SMTP connection to your client
227 machine and begin forwarding any items addressed to your client machine
228 in the server's queue of undelivered mail. The ODMR mode requires an
229 ODMR-capable server and works similarly to ETRN, except that it does
230 not require the client machine to have a static DNS.
231 -U | --uidl
233 (Keyword: uidl) Force UIDL use (effective only with POP3).
234 Force client-side tracking of 'newness' of messages (UIDL stands
235 for "unique ID listing" and is described in RFC1939). Use with
236 'keep' to use a mailbox as a baby news drop for a group of
237 users. The fact that seen messages are skipped is logged, unless
238 error logging is done through syslog while running in daemon
239 mode. Note that fetchmail may automatically enable this option
240 depending on upstream server capabilities. Note also that this
241 option may be removed and forced enabled in a future fetchmail
242 version. See also: --idfile.
243 --idle (since 6.3.3)
245 (Keyword: idle, since before 6.0.0) Enable IDLE use (effective
246 only with IMAP). Note that this works with only one folder at a
247 given time. While the idle rcfile keyword had been supported
248 for a long time, the --idle command-line option was added in
249 version 6.3.3. IDLE use means that fetchmail tells the IMAP
250 server to send notice of new messages, so they can be retrieved
251 sooner than would be possible with regular polls.
252 -P <portnumber> | --service <servicename>
254 (Keyword: service) Since version 6.3.0. The service option per‐
255 mits you to specify a service name to connect to. You can spec‐
256 ify a decimal port number here, if your services database lacks
257 the required service-port assignments. See the FAQ item R12 and
258 the --ssl documentation for details. This replaces the older
259 --port option.
260 --port <portnumber>
262 (Keyword: port) Obsolete version of --service that does not take
263 service names. Note: this option may be removed from a future
264 version.
265 --principal <principal>
267 (Keyword: principal) The principal option permits you to specify
268 a service principal for mutual authentication. This is applica‐
269 ble to POP3 or IMAP with Kerberos authentication.
270 -t <seconds> | --timeout <seconds>
272 (Keyword: timeout) The timeout option allows you to set a
273 server-nonresponse timeout in seconds. If a mailserver does not
274 send a greeting message or respond to commands for the given
275 number of seconds, fetchmail will hang up on it. Without such a
276 timeout fetchmail might hang up indefinitely trying to fetch
277 mail from a down host. This would be particularly annoying for
278 a fetchmail running in background. There is a default timeout
279 which fetchmail -V will report. If a given connection receives
280 too many timeouts in succession, fetchmail will consider it
281 wedged and stop retrying, the calling user will be notified by
282 email if this happens.
283 --plugin <command>
285 (Keyword: plugin) The plugin option allows you to use an exter‐
286 nal program to establish the TCP connection. This is useful if
287 you want to use socks, SSL, ssh, or need some special fire‐
288 walling setup. The program will be looked up in $PATH and can
289 optionally be passed the hostname and port as arguments using
290 "%h" and "%p" respectively (note that the interpolation logic is
291 rather primitive, and these token must be bounded by whitespace
292 or beginning of string or end of string). Fetchmail will write
293 to the plugin's stdin and read from the plugin's stdout.
294 --plugout <command>
296 (Keyword: plugout) Identical to the plugin option above, but
297 this one is used for the SMTP connections (which will probably
298 not need it, so it has been separated from plugin).
299 -r <name> | --folder <name>
301 (Keyword: folder[s]) Causes a specified non-default mail folder
302 on the mailserver (or comma-separated list of folders) to be
303 retrieved. The syntax of the folder name is server-dependent.
304 This option is not available under POP3, ETRN, or ODMR.
305 --tracepolls
307 (Keyword: tracepolls) Tell fetchmail to poll trace information
308 in the form 'polling %s account %s' and 'folder %s' to the
309 Received line it generates, where the %s parts are replaced by
310 the user's remote name, the poll label, and the folder (mailbox)
311 where available (the Received header also normally includes the
312 server's true name). This can be used to facilitate mail fil‐
313 tering based on the account it is being received from. The
314 folder information is written only since version 6.3.4.
315 --ssl (Keyword: ssl) Causes the connection to the mail server to be
317 encrypted via SSL. Connect to the server using the specified
318 base protocol over a connection secured by SSL. This option
319 defeats TLS negotiation. Use --sslcertck to validate the cer‐
320 tificates presented by the server.
321 Note that fetchmail may still try to negotiate TLS even if this
323 option is not given. You can use the --sslproto option to defeat
324 this behavior or tell fetchmail to negotiate a particular SSL
325 protocol.
326 If no port is specified, the connection is attempted to the well
328 known port of the SSL version of the base protocol. This is
329 generally a different port than the port used by the base proto‐
330 col. For IMAP, this is port 143 for the clear protocol and port
331 993 for the SSL secured protocol, for POP3, it is port 110 for
332 the clear text and port 995 for the encrypted variant.
333 If your system lacks the corresponding entries from /etc/ser‐
335 vices, see the --service option and specify the numeric port
336 number as given in the previous paragraph (unless your ISP had
337 directed you to different ports, which is uncommon however).
338 --sslcert <name>
340 (Keyword: sslcert) Specifies the file name of the client side
341 public SSL certificate. Some SSL encrypted servers may require
342 client side keys and certificates for authentication. In most
343 cases, this is optional. This specifies the location of the
344 public key certificate to be presented to the server at the time
345 the SSL session is established. It is not required (but may be
346 provided) if the server does not require it. Some servers may
347 require it, some servers may request it but not require it, and
348 some servers may not request it at all. It may be the same file
349 as the private key (combined key and certificate file) but this
350 is not recommended.
351 NOTE: If you use client authentication, the user name is fetched
353 from the certificate's CommonName and overrides the name set
354 with --user.
355 --sslkey <name>
357 (Keyword: sslkey) Specifies the file name of the client side
358 private SSL key. Some SSL encrypted servers may require client
359 side keys and certificates for authentication. In most cases,
360 this is optional. This specifies the location of the private
361 key used to sign transactions with the server at the time the
362 SSL session is established. It is not required (but may be pro‐
363 vided) if the server does not require it. Some servers may
364 require it, some servers may request it but not require it, and
365 some servers may not request it at all. It may be the same file
366 as the public key (combined key and certificate file) but this
367 is not recommended. If a password is required to unlock the
368 key, it will be prompted for at the time just prior to estab‐
369 lishing the session to the server. This can cause some compli‐
370 cations in daemon mode.
371 --sslproto <name>
373 (Keyword: sslproto) Forces an SSL or TLS protocol. Possible val‐
374 ues are 'SSL2', 'SSL3', 'SSL23', and 'TLS1'. Try this if the
375 default handshake does not work for your server. Use this option
376 with negotiation when the server advertises STARTTLS or STLS,
377 use ''. This option, even if the argument is the empty string,
378 will also suppress the diagnostic 'SERVER: opportunistic upgrade
379 to TLS.' message in verbose mode. The default is to try appro‐
380 priate protocols depending on context.
381 --sslcertck
383 (Keyword: sslcertck) Causes fetchmail to strictly check the
384 server certificate against a set of local trusted certificates
385 (see the sslcertpath option). If the server certificate cannot
386 be obtained or is not signed by one of the trusted ones
387 (directly or indirectly), the SSL connection will fail, regard‐
388 less of the sslfingerprint option. Note that CRL are only sup‐
389 ported in OpenSSL 0.9.7 and newer! Your system clock should also
390 be reasonably accurate when using this option.
391 Note that this optional behavior may become default behavior in
393 future fetchmail versions.
394 --sslcertpath <directory>
396 (Keyword: sslcertpath) Sets the directory fetchmail uses to look
397 up local certificates. The default is your OpenSSL default one.
398 The directory must be hashed as OpenSSL expects it - every time
399 you add or modify a certificate in the directory, you need to
400 use the c_rehash tool (which comes with OpenSSL in the tools/
401 subdirectory).
402 --sslfingerprint <fingerprint>
404 (Keyword: sslfingerprint) Specify the fingerprint of the server
405 key (an MD5 hash of the key) in hexadecimal notation with colons
406 separating groups of two digits. The letter hex digits must be
407 in upper case. This is the default format OpenSSL uses, and the
408 one fetchmail uses to report the fingerprint when an SSL connec‐
409 tion is established. When this is specified, fetchmail will com‐
410 pare the server key fingerprint with the given one, and the con‐
411 nection will fail if they do not match regardless of the
412 sslcertck setting. The connection will also fail if fetchmail
413 cannot obtain an SSL certificate from the server. This can be
414 used to prevent man-in-the-middle attacks, but the finger print
415 from the server needs to be obtained or verified over a secure
416 channel, and certainly not over the same Internet connection
417 that fetchmail would use.
418 Using this option will prevent printing certificate verification
420 errors as long as --sslcertck is unset.
421 To obtain the fingerprint of a certificate stored in the file
423 cert.pem, try:
424 openssl x509 -in cert.pem -noout -md5 -fingerprint
426 For details, see x509(1ssl).
428 Delivery Control Options
430 -S <hosts> | --smtphost <hosts>
431 (Keyword: smtp[host]) Specify a hunt list of hosts to forward
432 mail to (one or more hostnames, comma-separated). Hosts are
433 tried in list order; the first one that is up becomes the for‐
434 warding target for the current run. If this option is not spec‐
435 ified, 'localhost' is used as the default. Each hostname may
436 have a port number following the host name. The port number is
437 separated from the host name by a slash; the default port is
438 "smtp". If you specify an absolute path name (beginning with a
439 /), it will be interpreted as the name of a UNIX socket accept‐
440 ing LMTP connections (such as is supported by the Cyrus IMAP
441 daemon) Example:
442 --smtphost server1,server2/2525,server3,/var/imap/socket/lmtp
444 This option can be used with ODMR, and will make fetchmail a
446 relay between the ODMR server and SMTP or LMTP receiver.
447 --fetchdomains <hosts>
449 (Keyword: fetchdomains) In ETRN or ODMR mode, this option speci‐
450 fies the list of domains the server should ship mail for once
451 the connection is turned around. The default is the FQDN of the
452 machine running fetchmail.
453 -D <domain> | --smtpaddress <domain>
455 (Keyword: smtpaddress) Specify the domain to be appended to
456 addresses in RCPT TO lines shipped to SMTP. When this is not
457 specified, the name of the SMTP server (as specified by --smt‐
458 phost) is used for SMTP/LMTP and 'localhost' is used for UNIX
459 socket/BSMTP.
460 --smtpname <user@domain>
462 (Keyword: smtpname) Specify the domain and user to be put in
463 RCPT TO lines shipped to SMTP. The default user is the current
464 local user.
465 -Z <nnn> | --antispam <nnn[, nnn]...>
467 (Keyword: antispam) Specifies the list of numeric SMTP errors
468 that are to be interpreted as a spam-block response from the
469 listener. A value of -1 disables this option. For the command-
470 line option, the list values should be comma-separated.
471 -m <command> | --mda <command>
473 (Keyword: mda) You can force mail to be passed to an MDA
474 directly (rather than forwarded to port 25) with the --mda or -m
475 option. To avoid losing mail, use this option only with MDAs
476 like maildrop or MTAs like sendmail that return a nonzero status
477 on disk-full and other resource-exhaustion errors; the nonzero
478 status tells fetchmail that delivery failed and prevents the
479 message from being deleted off the server. If fetchmail is run‐
480 ning as root, it sets its user id to that of the target user
481 while delivering mail through an MDA. Some possible MDAs are
482 "/usr/sbin/sendmail -i -f %F -- %T" (Note: some several older or
483 vendor sendmail versions mistake -- for an address, rather than
484 an indicator to mark the end of the option arguments),
485 "/usr/bin/deliver" and "/usr/bin/maildrop -d %T". Local deliv‐
486 ery addresses will be inserted into the MDA command wherever you
487 place a %T; the mail message's From address will be inserted
488 where you place an %F. DO NOT ENCLOSE THE %F OR %T STRING IN
489 SINGLE QUOTES! For both %T and %F, fetchmail encloses the
490 addresses in single quotes ('), after removing any single quotes
491 they may contain, before the MDA command is passed to the shell.
492 Do NOT use an MDA invocation like "sendmail -i -t" that dis‐
493 patches on the contents of To/Cc/Bcc, it will create mail loops
494 and bring the just wrath of many postmasters down upon your
495 head. Also, do not try to combine multidrop mode with an MDA
496 such as maildrop that can only accept one address; you will lose
497 mail.
498 A word of warning: the well-known procmail(1) package is very
500 hard to configure properly, it has a very nasty "fall through to
501 the next rule" behavior on delivery errors (even temporary ones,
502 such as out of disk space if another user's mail daemon copies
503 the mailbox around to purge old messages), so your mail will end
504 up in the wrong mailbox sooner or later. The proper procmail
505 configuration is outside the scope of this document though.
506 Using maildrop(1) is usually much easier, and many users find
507 the filter syntax used by maildrop easier to understand.
508 --lmtp (Keyword: lmtp) Cause delivery via LMTP (Local Mail Transfer
511 Protocol). A service host and port must be explicitly specified
512 on each host in the smtphost hunt list (see above) if this
513 option is selected; the default port 25 will (in accordance with
514 RFC 2033) not be accepted.
515 --bsmtp <filename>
517 (keyword: bsmtp) Append fetched mail to a BSMTP file. This sim‐
518 ply contains the SMTP commands that would normally be generated
519 by fetchmail when passing mail to an SMTP listener daemon. An
520 argument of '-' causes the mail to be written to standard out‐
521 put. Note that fetchmail's reconstruction of MAIL FROM and RCPT
522 TO lines is not guaranteed correct; the caveats discussed under
523 THE USE AND ABUSE OF MULTIDROP MAILBOXES below apply.
524 Resource Limit Control Options
526 -l <maxbytes> | --limit <maxbytes>
527 (Keyword: limit) Takes a maximum octet size argument. Messages
528 larger than this size will not be fetched and will be left on
529 the server (in foreground sessions, the progress messages will
530 note that they are "oversized"). If the fetch protocol permits
531 (in particular, under IMAP or POP3 without the fetchall option)
532 the message will not be marked seen.
533 An explicit --limit of 0 overrides any limits set in your run
535 control file. This option is intended for those needing to
536 strictly control fetch time due to expensive and variable phone
537 rates.
538 Combined with --limitflush, it can be used to delete oversized
540 messages waiting on a server. In daemon mode, oversize notifi‐
541 cations are mailed to the calling user (see the --warnings
542 option). This option does not work with ETRN or ODMR.
543 -w <interval> | --warnings <interval>
545 (Keyword: warnings) Takes an interval in seconds. When you call
546 fetchmail with a 'limit' option in daemon mode, this controls
547 the interval at which warnings about oversized messages are
548 mailed to the calling user (or the user specified by the 'post‐
549 master' option). One such notification is always mailed at the
550 end of the the first poll that the oversized message is
551 detected. Thereafter, re-notification is suppressed until after
552 the warning interval elapses (it will take place at the end of
553 the first following poll).
554 -b <count> | --batchlimit <count>
556 (Keyword: batchlimit) Specify the maximum number of messages
557 that will be shipped to an SMTP listener before the connection
558 is deliberately torn down and rebuilt (defaults to 0, meaning no
559 limit). An explicit --batchlimit of 0 overrides any limits set
560 in your run control file. While sendmail(8) normally initiates
561 delivery of a message immediately after receiving the message
562 terminator, some SMTP listeners are not so prompt. MTAs like
563 smail(8) may wait till the delivery socket is shut down to
564 deliver. This may produce annoying delays when fetchmail is
565 processing very large batches. Setting the batch limit to some
566 nonzero size will prevent these delays. This option does not
567 work with ETRN or ODMR.
568 -B <number> | --fetchlimit <number>
570 (Keyword: fetchlimit) Limit the number of messages accepted from
571 a given server in a single poll. By default there is no limit.
572 An explicit --fetchlimit of 0 overrides any limits set in your
573 run control file. This option does not work with ETRN or ODMR.
574 --fetchsizelimit <number>
576 (Keyword: fetchsizelimit) Limit the number of sizes of messages
577 accepted from a given server in a single transaction. This
578 option is useful in reducing the delay in downloading the first
579 mail when there are too many mails in the mailbox. By default,
580 the limit is 100. If set to 0, sizes of all messages are down‐
581 loaded at the start. This option does not work with ETRN or
582 ODMR. For POP3, the only valid non-zero value is 1.
583 --fastuidl <number>
585 (Keyword: fastuidl) Do a binary instead of linear search for the
586 first unseen UID. Binary search avoids downloading the UIDs of
587 all mails. This saves time (especially in daemon mode) where
588 downloading the same set of UIDs in each poll is a waste of
589 bandwidth. The number 'n' indicates how rarely a linear search
590 should be done. In daemon mode, linear search is used once fol‐
591 lowed by binary searches in 'n-1' polls if 'n' is greater than
592 1; binary search is always used if 'n' is 1; linear search is
593 always used if 'n' is 0. In non-daemon mode, binary search is
594 used if 'n' is 1; otherwise linear search is used. The default
595 value of 'n' is 4. This option works with POP3 only.
596 -e <count> | --expunge <count>
598 (keyword: expunge) Arrange for deletions to be made final after
599 a given number of messages. Under POP2 or POP3, fetchmail can‐
600 not make deletions final without sending QUIT and ending the
601 session -- with this option on, fetchmail will break a long mail
602 retrieval session into multiple sub-sessions, sending QUIT after
603 each sub-session. This is a good defense against line drops on
604 POP3 servers. Under IMAP, fetchmail normally issues an EXPUNGE
605 command after each deletion in order to force the deletion to be
606 done immediately. This is safest when your connection to the
607 server is flaky and expensive, as it avoids resending duplicate
608 mail after a line hit. However, on large mailboxes the overhead
609 of re-indexing after every message can slam the server pretty
610 hard, so if your connection is reliable it is good to do
611 expunges less frequently. Also note that some servers enforce a
612 delay of a few seconds after each quit, so fetchmail may not be
613 able to get back in immediately after an expunge -- you may see
614 "lock busy" errors if this happens. If you specify this option
615 to an integer N, it tells fetchmail to only issue expunges on
616 every Nth delete. An argument of zero suppresses expunges
617 entirely (so no expunges at all will be done until the end of
618 run). This option does not work with ETRN or ODMR.
619 Authentication Options
621 -u <name> | --user <name> | --username <name>
622 (Keyword: user[name]) Specifies the user identification to be
623 used when logging in to the mailserver. The appropriate user
624 identification is both server and user-dependent. The default
625 is your login name on the client machine that is running fetch‐
626 mail. See USER AUTHENTICATION below for a complete description.
627 -I <specification> | --interface <specification>
629 (Keyword: interface) Require that a specific interface device be
630 up and have a specific local or remote IPv4 (IPv6 is not sup‐
631 ported by this option yet) address (or range) before polling.
632 Frequently fetchmail is used over a transient point-to-point
633 TCP/IP link established directly to a mailserver via SLIP or
634 PPP. That is a relatively secure channel. But when other
635 TCP/IP routes to the mailserver exist (e.g. when the link is
636 connected to an alternate ISP), your username and password may
637 be vulnerable to snooping (especially when daemon mode automati‐
638 cally polls for mail, shipping a clear password over the net at
639 predictable intervals). The --interface option may be used to
640 prevent this. When the specified link is not up or is not con‐
641 nected to a matching IP address, polling will be skipped. The
642 format is:
643 interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]
645 The field before the first slash is the interface name (i.e.
647 sl0, ppp0 etc.). The field before the second slash is the
648 acceptable IP address. The field after the second slash is a
649 mask which specifies a range of IP addresses to accept. If no
650 mask is present 255.255.255.255 is assumed (i.e. an exact
651 match). This option is currently only supported under Linux and
652 FreeBSD. Please see the monitor section for below for FreeBSD
653 specific information.
654 Note that this option may be removed from a future fetchmail
656 version.
657 -M <interface> | --monitor <interface>
659 (Keyword: monitor) Daemon mode can cause transient links which
660 are automatically taken down after a period of inactivity (e.g.
661 PPP links) to remain up indefinitely. This option identifies a
662 system TCP/IP interface to be monitored for activity. After
663 each poll interval, if the link is up but no other activity has
664 occurred on the link, then the poll will be skipped. However,
665 when fetchmail is woken up by a signal, the monitor check is
666 skipped and the poll goes through unconditionally. This option
667 is currently only supported under Linux and FreeBSD. For the
668 monitor and interface options to work for non root users under
669 FreeBSD, the fetchmail binary must be installed SGID kmem. This
670 would be a security hole, but fetchmail runs with the effective
671 GID set to that of the kmem group only when interface data is
672 being collected.
673 Note that this option may be removed from a future fetchmail
675 version.
676 --auth <type>
678 (Keyword: auth[enticate]) This option permits you to specify an
679 authentication type (see USER AUTHENTICATION below for details).
680 The possible values are any, password, kerberos_v5, kerberos
681 (or, for excruciating exactness, kerberos_v4), gssapi, cram-md5,
682 otp, ntlm, msn (only for POP3), external (only IMAP) and ssh.
683 When any (the default) is specified, fetchmail tries first meth‐
684 ods that don't require a password (EXTERNAL, GSSAPI, KER‐
685 BEROS IV, KERBEROS 5); then it looks for methods that mask your
686 password (CRAM-MD5, X-OTP - note that NTLM and MSN are not auto‐
687 probed for POP3 and MSN is only supported for POP3); and only if
688 the server doesn't support any of those will it ship your pass‐
689 word en clair. Other values may be used to force various
690 authentication methods (ssh suppresses authentication and is
691 thus useful for IMAP PREAUTH). (external suppresses authentica‐
692 tion and is thus useful for IMAP EXTERNAL). Any value other
693 than password, cram-md5, ntlm, msn or otp suppresses fetchmail's
694 normal inquiry for a password. Specify ssh when you are using
695 an end-to-end secure connection such as an ssh tunnel; specify
696 external when you use TLS with client authentication and specify
697 gssapi or kerberos_v4 if you are using a protocol variant that
698 employs GSSAPI or K4. Choosing KPOP protocol automatically
699 selects Kerberos authentication. This option does not work with
700 ETRN.
701 Miscellaneous Options
703 -f <pathname> | --fetchmailrc <pathname>
704 Specify a non-default name for the ~/.fetchmailrc run control
705 file. The pathname argument must be either "-" (a single dash,
706 meaning to read the configuration from standard input) or a
707 filename. Unless the --version option is also on, a named file
708 argument must have permissions no more open than 0600
709 (u=rw,g=,o=) or else be /dev/null.
710 -i <pathname> | --idfile <pathname>
712 (Keyword: idfile) Specify an alternate name for the .fetchids
713 file used to save POP3 UIDs. NOTE: since fetchmail 6.3.0, write
714 access to the directory containing the idfile is required, as
715 fetchmail writes a temporary file and renames it into the place
716 of the real idfile only if the temporary file has been written
717 successfully. This avoids the truncation of idfiles when running
718 out of disk space.
719 --pidfile <pathname>
721 (Keyword: pidfile; since fetchmail v6.3.4) Override the default
722 location of the PID file. Default: see "ENVIRONMENT" below.
723 -n | --norewrite
725 (Keyword: no rewrite) Normally, fetchmail edits RFC-822 address
726 headers (To, From, Cc, Bcc, and Reply-To) in fetched mail so
727 that any mail IDs local to the server are expanded to full
728 addresses (@ and the mailserver hostname are appended). This
729 enables replies on the client to get addressed correctly (other‐
730 wise your mailer might think they should be addressed to local
731 users on the client machine!). This option disables the re‐
732 write. (This option is provided to pacify people who are para‐
733 noid about having an MTA edit mail headers and want to know they
734 can prevent it, but it is generally not a good idea to actually
735 turn off rewrite.) When using ETRN or ODMR, the rewrite option
736 is ineffective.
737 -E <line> | --envelope <line>
739 (Keyword: envelope; Multidrop only)
740 In the configuration file, an enhanced syntax is used:
741 envelope [<count>] <line>
742 This option changes the header fetchmail assumes will carry a
744 copy of the mail's envelope address. Normally this is 'X-Enve‐
745 lope-To', but as this header is not standard, practice varies.
746 See the discussion of multidrop address handling below. As a
747 special case, 'envelope "Received"' enables parsing of sendmail-
748 style Received lines. This is the default, and it should not be
749 necessary unless you have globally disabled Received parsing
750 with 'no envelope' in the .fetchmailrc file.
751 The optional count argument (only available in the configuration
753 file) determines how many header lines of this kind are skipped.
754 A count of 1 means: skip the first, take the second. A count of
755 2 means: skip the first and second, take the third, and so on.
756 -Q <prefix> | --qvirtual <prefix>
758 (Keyword: qvirtual; Multidrop only) The string prefix assigned
759 to this option will be removed from the user name found in the
760 header specified with the envelope option (before doing mul‐
761 tidrop name mapping or localdomain checking, if either is appli‐
762 cable). This option is useful if you are using fetchmail to col‐
763 lect the mail for an entire domain and your ISP (or your mail
764 redirection provider) is using qmail. One of the basic features
765 of qmail is the
766 'Delivered-To:'
768 message header. Whenever qmail delivers a message to a local
770 mailbox it puts the username and hostname of the envelope recip‐
771 ient on this line. The major reason for this is to prevent mail
772 loops. To set up qmail to batch mail for a disconnected site
773 the ISP-mailhost will have normally put that site in its 'Virtu‐
774 alhosts' control file so it will add a prefix to all mail
775 addresses for this site. This results in mail sent to 'user‐
776 name@userhost.userdom.dom.com' having a 'Delivered-To:' line of
777 the form:
778 Delivered-To: mbox-userstr-username@userhost.example.com
780 The ISP can make the 'mbox-userstr-' prefix anything they choose
782 but a string matching the user host name is likely. By using
783 the option 'envelope Delivered-To:' you can make fetchmail reli‐
784 ably identify the original envelope recipient, but you have to
785 strip the 'mbox-userstr-' prefix to deliver to the correct user.
786 This is what this option is for.
787 --configdump
789 Parse the ~/.fetchmailrc file, interpret any command-line
790 options specified, and dump a configuration report to standard
791 output. The configuration report is a data structure assignment
792 in the language Python. This option is meant to be used with an
793 interactive ~/.fetchmailrc editor like fetchmailconf, written in
794 Python.
795 Removed Options
797 -T | --netsec
798 Removed before version 6.3.0, the required underlying inet6_apps
799 library had been discontinued and is no longer available.
800
803 All modes except ETRN require authentication of the client to the
804 server. Normal user authentication in fetchmail is very much like the
805 authentication mechanism of ftp(1). The correct user-id and password
806 depend upon the underlying security system at the mailserver.
807 If the mailserver is a Unix machine on which you have an ordinary user
809 account, your regular login name and password are used with fetchmail.
810 If you use the same login name on both the server and the client
811 machines, you needn't worry about specifying a user-id with the -u
812 option -- the default behavior is to use your login name on the client
813 machine as the user-id on the server machine. If you use a different
814 login name on the server machine, specify that login name with the -u
815 option. e.g. if your login name is 'jsmith' on a machine named 'mail‐
816 grunt', you would start fetchmail as follows:
817 fetchmail -u jsmith mailgrunt
819 The default behavior of fetchmail is to prompt you for your mailserver
821 password before the connection is established. This is the safest way
822 to use fetchmail and ensures that your password will not be compro‐
823 mised. You may also specify your password in your ~/.fetchmailrc file.
824 This is convenient when using fetchmail in daemon mode or with scripts.
825 Using netrc files
827 If you do not specify a password, and fetchmail cannot extract one from
828 your ~/.fetchmailrc file, it will look for a ~/.netrc file in your home
829 directory before requesting one interactively; if an entry matching the
830 mailserver is found in that file, the password will be used. Fetchmail
831 first looks for a match on poll name; if it finds none, it checks for a
832 match on via name. See the ftp(1) man page for details of the syntax
833 of the ~/.netrc file. To show a practical example, a .netrc might look
834 like this:
835 machine hermes.example.org
837 login joe
838 password topsecret
839 You can repeat this block with different user information if you need
841 to provide more than one password.
842 This feature may allow you to avoid duplicating password information in
844 more than one file.
845 On mailservers that do not provide ordinary user accounts, your user-id
847 and password are usually assigned by the server administrator when you
848 apply for a mailbox on the server. Contact your server administrator
849 if you don't know the correct user-id and password for your mailbox
850 account.
851
853 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
854 independent authentication using the rhosts file on the mailserver
855 side. Under this RPOP variant, a fixed per-user ID equivalent to a
856 password was sent in clear over a link to a reserved port, with the
857 command RPOP rather than PASS to alert the server that it should do
858 special checking. RPOP is supported by fetchmail (you can specify
859 'protocol RPOP' to have the program send 'RPOP' rather than 'PASS') but
860 its use is strongly discouraged, and support will be removed from a
861 future fetchmail version. This facility was vulnerable to spoofing and
862 was withdrawn in RFC1460.
863 RFC1460 introduced APOP authentication. In this variant of POP3, you
865 register an APOP password on your server host (the program to do this
866 with on the server is probably called popauth(8)). You put the same
867 password in your ~/.fetchmailrc file. Each time fetchmail logs in, it
868 sends a cryptographically secure hash of your password and the server
869 greeting time to the server, which can verify it by checking its autho‐
870 rization database.
871 RETR or TOP
873 fetchmail makes some efforts to make the server believe messages had
874 not been retrieved, by using the TOP command with a large number of
875 lines when possible. TOP is a command that retrieves the full header
876 and a fetchmail-specified amount of body lines. It is optional and
877 therefore not implemented by all servers, and some are known to imple‐
878 ment it improperly. On many servers however, the RETR command which
879 retrieves the full message with header and body, sets the "seen" flag
880 (for instance, in a web interface), whereas the TOP command does not do
881 that.
882 fetchmail will always use the RETR command if "fetchall" is set.
884 fetchmail will also use the RETR command if "keep" is set and "uidl" is
885 unset. Finally, fetchmail will use the RETR command on Maillennium
886 POP3/PROXY servers (used by Comcast) to avoid a deliberate TOP misin‐
887 terpretation in this server that causes message corruption.
888 In all other cases, fetchmail will use the TOP command. This implies
890 that in "keep" setups, "uidl" must be set if "TOP" is desired.
891 Note that this description is true for the current version of fetch‐
893 mail, but the behavior may change in future versions. In particular,
894 fetchmail may prefer the RETR command because the TOP command causes
895 much grief on some servers and is only optional.
896
898 If your fetchmail was built with Kerberos support and you specify Ker‐
899 beros authentication (either with --auth or the .fetchmailrc option
900 authenticate kerberos_v4) it will try to get a Kerberos ticket from the
901 mailserver at the start of each query. Note: if either the pollname or
902 via name is 'hesiod', fetchmail will try to use Hesiod to look up the
903 mailserver.
904 If you use POP3 or IMAP with GSSAPI authentication, fetchmail will
906 expect the server to have RFC1731- or RFC1734-conforming GSSAPI capa‐
907 bility, and will use it. Currently this has only been tested over Ker‐
908 beros V, so you're expected to already have a ticket-granting ticket.
909 You may pass a username different from your principal name using the
910 standard --user command or by the .fetchmailrc option user.
911 If your IMAP daemon returns the PREAUTH response in its greeting line,
913 fetchmail will notice this and skip the normal authentication step.
914 This can be useful, e.g. if you start imapd explicitly using ssh. In
915 this case you can declare the authentication value 'ssh' on that site
916 entry to stop .fetchmail from asking you for a password when it starts
917 up.
918 If you use client authentication with TLS1 and your IMAP daemon returns
920 the AUTH=EXTERNAL response, fetchmail will notice this and will use the
921 authentication shortcut and will not send the passphrase. In this case
922 you can declare the authentication value 'external'
923 on that site to stop fetchmail from asking you for a password when it
924 starts up.
925 If you are using POP3, and the server issues a one-time-password chal‐
927 lenge conforming to RFC1938, fetchmail will use your password as a pass
928 phrase to generate the required response. This avoids sending secrets
929 over the net unencrypted.
930 Compuserve's RPA authentication (similar to APOP) is supported. If you
932 compile in the support, fetchmail will try to perform an RPA pass-
933 phrase authentication instead of sending over the password en clair if
934 it detects "@compuserve.com" in the hostname.
935 If you are using IMAP, Microsoft's NTLM authentication (used by Micro‐
937 soft Exchange) is supported. If you compile in the support, fetchmail
938 will try to perform an NTLM authentication (instead of sending over the
939 password en clair) whenever the server returns AUTH=NTLM in its capa‐
940 bility response. Specify a user option value that looks like
941 'user@domain': the part to the left of the @ will be passed as the
942 username and the part to the right as the NTLM domain.
943 Secure Socket Layers (SSL) and Transport Layer Security (TLS)
945 You can access SSL encrypted services by specifying the --ssl option.
946 You can also do this using the "ssl" user option in the .fetchmailrc
947 file. With SSL encryption enabled, queries are initiated over a connec‐
948 tion after negotiating an SSL session, and the connection fails if SSL
949 cannot be negotiated. Some services, such as POP3 and IMAP, have dif‐
950 ferent well known ports defined for the SSL encrypted services. The
951 encrypted ports will be selected automatically when SSL is enabled and
952 no explicit port is specified. The --sslproto option can be used to
953 select the SSL protocols (default: v2 or v3). The --sslcertck command
954 line or sslcertck run control file option should be used to force
955 strict certificate checking - see below.
956 If SSL is not configured, fetchmail will usually opportunistically try
958 to use TLS. TLS can be enforced by using --sslproto "TLS1". TLS connec‐
959 tions use the same port as the unencrypted version of the protocol and
960 negotiate TLS via special parameter. The --sslcertck command line or
961 sslcertck run control file option should be used to force strict cer‐
962 tificate checking - see below.
963 --sslcheck recommended: When connecting to an SSL or TLS encrypted
965 server, the server presents a certificate to the client for validation.
966 The certificate is checked to verify that the common name in the cer‐
967 tificate matches the name of the server being contacted and that the
968 effective and expiration dates in the certificate indicate that it is
969 currently valid. If any of these checks fail, a warning message is
970 printed, but the connection continues. The server certificate does not
971 need to be signed by any specific Certifying Authority and may be a
972 "self-signed" certificate. If the --sslcertck command line option or
973 sslcertck run control file option is used, fetchmail will instead abort
974 if any of these checks fail. Use of the sslcertck or --sslcertck option
975 is advised.
976 Some SSL encrypted servers may request a client side certificate. A
978 client side public SSL certificate and private SSL key may be speci‐
979 fied. If requested by the server, the client certificate is sent to
980 the server for validation. Some servers may require a valid client
981 certificate and may refuse connections if a certificate is not provided
982 or if the certificate is not valid. Some servers may require client
983 side certificates be signed by a recognized Certifying Authority. The
984 format for the key files and the certificate files is that required by
985 the underlying SSL libraries (OpenSSL in the general case).
986 A word of care about the use of SSL: While above mentioned setup with
988 self-signed server certificates retrieved over the wires can protect
989 you from a passive eavesdropper, it doesn't help against an active
990 attacker. It's clearly an improvement over sending the passwords in
991 clear, but you should be aware that a man-in-the-middle attack is triv‐
992 ially possible (in particular with tools such as dsniff, http://mon‐
993 key.org/~dugsong/dsniff/). Use of strict certificate checking with a
994 certification authority recognized by server and client, or perhaps of
995 an SSH tunnel (see below for some examples) is preferable if you care
996 seriously about the security of your mailbox and passwords.
997 ESMTP AUTH
999 fetchmail also supports authentication to the ESMTP server on the
1000 client side according to RFC 2554. You can specify a name/password
1001 pair to be used with the keywords 'esmtpname' and 'esmtppassword'; the
1002 former defaults to the username of the calling user.
1003
1006 Introducing the daemon mode
1007 In daemon mode, fetchmail puts itself into the background and runs for‐
1008 ever, querying each specified host and then sleeping for a given
1009 polling interval.
1010 Starting the daemon mode
1012 There are several ways to make fetchmail work in daemon mode. On the
1013 command line, --daemon <interval> or -d <interval> option runs fetch‐
1014 mail in daemon mode. You must specify a numeric argument which is a
1015 polling interval in seconds.
1016 Example: simply invoking
1018 fetchmail -d 900
1020 will, therefore, poll all the hosts described in your ~/.fetchmailrc
1022 file (except those explicitly excluded with the 'skip' verb) once every
1023 15 minutes.
1024 It is also possible to set a polling interval in your ~/.fetchmailrc
1026 file by saying 'set daemon <interval>', where <interval> is an integer
1027 number of seconds. If you do this, fetchmail will always start in dae‐
1028 mon mode unless you override it with the command-line option --daemon 0
1029 or -d0.
1030 Only one daemon process is permitted per user; in daemon mode, fetch‐
1032 mail sets up a per-user lockfile to guarantee this. (You can however
1033 cheat and set the FETCHMAILHOME environment variable to overcome this
1034 setting, but in that case, it is your responsibility to make sure you
1035 aren't polling the same server with two processes at the same time.)
1036 Awakening the background daemon
1038 Normally, calling fetchmail with a daemon in the background sends a
1039 wake-up signal to the daemon and quits without output. The background
1040 daemon then starts its next poll cycle immediately. The wake-up sig‐
1041 nal, SIGUSR1, can also be sent manually. The wake-up action also clears
1042 any authentication or multiple timeouts.
1043 Terminating the background daemon
1045 The option --quit will kill a running daemon process instead of waking
1046 it up (if there is no such process, fetchmail will notify you. If the
1047 --quit option appears last on the command line, fetchmail will kill the
1048 running daemon process and then quit. Otherwise, fetchmail will first
1049 kill a running daemon process and then continue running with the other
1050 options.
1051 Useful options for daemon mode
1053 The -L <filename> or --logfile <filename> option (keyword: set logfile)
1054 is only effective when fetchmail is detached. This option allows you to
1055 redirect status messages into a specified logfile (follow the option
1056 with the logfile name). The logfile is opened for append, so previous
1057 messages aren't deleted. This is primarily useful for debugging con‐
1058 figurations. Note that fetchmail does not detect if the logfile is
1059 rotated, the logfile is only opened once when fetchmail starts. You
1060 need to restart fetchmail after rotating the logfile and before com‐
1061 pressing it (if applicable).
1062 The --syslog option (keyword: set syslog) allows you to redirect status
1064 and error messages emitted to the syslog(3) system daemon if available.
1065 Messages are logged with an id of fetchmail, the facility LOG_MAIL, and
1066 priorities LOG_ERR, LOG_ALERT or LOG_INFO. This option is intended for
1067 logging status and error messages which indicate the status of the dae‐
1068 mon and the results while fetching mail from the server(s). Error mes‐
1069 sages for command line options and parsing the .fetchmailrc file are
1070 still written to stderr, or to the specified log file. The --nosyslog
1071 option turns off use of syslog(3), assuming it's turned on in the
1072 ~/.fetchmailrc file, or that the -L or --logfile <file> option was
1073 used.
1074 The -N or --nodetach option suppresses backgrounding and detachment of
1076 the daemon process from its control terminal. This is useful for
1077 debugging or when fetchmail runs as the child of a supervisor process
1078 such as init(8) or Gerrit Pape's runit. Note that this also causes the
1079 logfile option to be ignored (though perhaps it shouldn't).
1080 Note that while running in daemon mode polling a POP2 or IMAP2bis
1082 server, transient errors (such as DNS failures or sendmail delivery
1083 refusals) may force the fetchall option on for the duration of the next
1084 polling cycle. This is a robustness feature. It means that if a mes‐
1085 sage is fetched (and thus marked seen by the mailserver) but not deliv‐
1086 ered locally due to some transient error, it will be re-fetched during
1087 the next poll cycle. (The IMAP logic doesn't delete messages until
1088 they're delivered, so this problem does not arise.)
1089 If you touch or change the ~/.fetchmailrc file while fetchmail is run‐
1091 ning in daemon mode, this will be detected at the beginning of the next
1092 poll cycle. When a changed ~/.fetchmailrc is detected, fetchmail
1093 rereads it and restarts from scratch (using exec(2); no state informa‐
1094 tion is retained in the new instance). Note also that if you break the
1095 ~/.fetchmailrc file's syntax, the new instance will softly and silently
1096 vanish away on startup.
1097
1100 The --postmaster <name> option (keyword: set postmaster) specifies the
1101 last-resort username to which multidrop mail is to be forwarded if no
1102 matching local recipient can be found. It is also used as destination
1103 of undeliverable mail if the 'bouncemail' global option is off and
1104 additionally for spam-blocked mail if the 'bouncemail' global option is
1105 off and the 'spambounce' global option is on. This option defaults to
1106 the user who invoked fetchmail. If the invoking user is root, then the
1107 default of this option is the user 'postmaster'. Setting postmaster to
1108 the empty string causes such mail as described above to be discarded -
1109 this however is usually a bad idea. See also the description of the
1110 'FETCHMAILUSER' environment variable in the ENVIRONMENT section below.
1111 The --nobounce behaves like the "set no bouncemail" global option,
1113 which see.
1114 The --invisible option (keyword: set invisible) tries to make fetchmail
1116 invisible. Normally, fetchmail behaves like any other MTA would -- it
1117 generates a Received header into each message describing its place in
1118 the chain of transmission, and tells the MTA it forwards to that the
1119 mail came from the machine fetchmail itself is running on. If the
1120 invisible option is on, the Received header is suppressed and fetchmail
1121 tries to spoof the MTA it forwards to into thinking it came directly
1122 from the mailserver host.
1123 The --showdots option (keyword: set showdots) forces fetchmail to show
1125 progress dots even if the current tty is not stdout (for example log‐
1126 files). Fetchmail shows the dots by default when run in nodetach mode
1127 or when daemon mode is not enabled.
1128 By specifying the --tracepolls option, you can ask fetchmail to add
1130 information to the Received header on the form "polling {label} account
1131 {user}", where {label} is the account label (from the specified rcfile,
1132 normally ~/.fetchmailrc) and {user} is the username which is used to
1133 log on to the mail server. This header can be used to make filtering
1134 email where no useful header information is available and you want mail
1135 from different accounts sorted into different mailboxes (this could,
1136 for example, occur if you have an account on the same server running a
1137 mailing list, and are subscribed to the list using that account). The
1138 default is not adding any such header. In .fetchmailrc, this is called
1139 'tracepolls'.
1140
1143 The protocols fetchmail uses to talk to mailservers are next to bullet‐
1144 proof. In normal operation forwarding to port 25, no message is ever
1145 deleted (or even marked for deletion) on the host until the SMTP lis‐
1146 tener on the client side has acknowledged to fetchmail that the message
1147 has been either accepted for delivery or rejected due to a spam block.
1148 When forwarding to an MDA, however, there is more possibility of error.
1150 Some MDAs are 'safe' and reliably return a nonzero status on any deliv‐
1151 ery error, even one due to temporary resource limits. The maildrop(1)
1152 program is like this; so are most programs designed as mail transport
1153 agents, such as sendmail(1), including the sendmail wrapper of Postfix
1154 and exim(1). These programs give back a reliable positive acknowledge‐
1155 ment and can be used with the mda option with no risk of mail loss.
1156 Unsafe MDAs, though, may return 0 even on delivery failure. If this
1157 happens, you will lose mail.
1158 The normal mode of fetchmail is to try to download only 'new' messages,
1160 leaving untouched (and undeleted) messages you have already read
1161 directly on the server (or fetched with a previous fetchmail --keep).
1162 But you may find that messages you've already read on the server are
1163 being fetched (and deleted) even when you don't specify --all. There
1164 are several reasons this can happen.
1165 One could be that you're using POP2. The POP2 protocol includes no
1167 representation of 'new' or 'old' state in messages, so fetchmail must
1168 treat all messages as new all the time. But POP2 is obsolete, so this
1169 is unlikely.
1170 A potential POP3 problem might be servers that insert messages in the
1172 middle of mailboxes (some VMS implementations of mail are rumored to do
1173 this). The fetchmail code assumes that new messages are appended to
1174 the end of the mailbox; when this is not true it may treat some old
1175 messages as new and vice versa. Using UIDL whilst setting fastuidl 0
1176 might fix this, otherwise, consider switching to IMAP.
1177 Yet another POP3 problem is that if they can't make tempfiles in the
1179 user's home directory, some POP3 servers will hand back an undocumented
1180 response that causes fetchmail to spuriously report "No mail".
1181 The IMAP code uses the presence or absence of the server flag \Seen to
1183 decide whether or not a message is new. This isn't the right thing to
1184 do, fetchmail should check the UIDVALIDITY and use UID, but it doesn't
1185 do that yet. Under Unix, it counts on your IMAP server to notice the
1186 BSD-style Status flags set by mail user agents and set the \Seen flag
1187 from them when appropriate. All Unix IMAP servers we know of do this,
1188 though it's not specified by the IMAP RFCs. If you ever trip over a
1189 server that doesn't, the symptom will be that messages you have already
1190 read on your host will look new to the server. In this (unlikely)
1191 case, only messages you fetched with fetchmail --keep will be both
1192 undeleted and marked old.
1193 In ETRN and ODMR modes, fetchmail does not actually retrieve messages;
1195 instead, it asks the server's SMTP listener to start a queue flush to
1196 the client via SMTP. Therefore it sends only undelivered messages.
1197
1200 Many SMTP listeners allow administrators to set up 'spam filters' that
1201 block unsolicited email from specified domains. A MAIL FROM or DATA
1202 line that triggers this feature will elicit an SMTP response which
1203 (unfortunately) varies according to the listener.
1204 Newer versions of sendmail return an error code of 571.
1206 According to RFC2821, the correct thing to return in this situation is
1208 550 "Requested action not taken: mailbox unavailable" (the draft adds
1209 "[E.g., mailbox not found, no access, or command rejected for policy
1210 reasons].").
1211 Older versions of the exim MTA return 501 "Syntax error in parameters
1213 or arguments".
1214 The postfix MTA runs 554 as an antispam response.
1216 Zmailer may reject code with a 500 response (followed by an enhanced
1218 status code that contains more information).
1219 Return codes which fetchmail treats as antispam responses and discards
1221 the message can be set with the 'antispam' option. This is one of the
1222 only three circumstance under which fetchmail ever discards mail (the
1223 others are the 552 and 553 errors described below, and the suppression
1224 of multidropped messages with a message-ID already seen).
1225 If fetchmail is fetching from an IMAP server, the antispam response
1227 will be detected and the message rejected immediately after the headers
1228 have been fetched, without reading the message body. Thus, you won't
1229 pay for downloading spam message bodies.
1230 By default, the list of antispam responses is empty.
1232 If the spambounce global option is on, mail that is spam-blocked trig‐
1234 gers an RFC1892/RFC1894 bounce message informing the originator that we
1235 do not accept mail from it. See also BUGS.
1236
1239 Besides the spam-blocking described above, fetchmail takes special
1240 actions on the following SMTP/ESMTP error responses
1241 452 (insufficient system storage)
1243 Leave the message in the server mailbox for later retrieval.
1244 552 (message exceeds fixed maximum message size)
1246 Delete the message from the server. Send bounce-mail to the orig‐
1247 inator.
1248 553 (invalid sending domain)
1250 Delete the message from the server. Don't even try to send
1251 bounce-mail to the originator.
1252 Other errors trigger bounce mail back to the originator. See also BUGS.
1254
1257 The preferred way to set up fetchmail is to write a .fetchmailrc file
1258 in your home directory (you may do this directly, with a text editor,
1259 or indirectly via fetchmailconf). When there is a conflict between the
1260 command-line arguments and the arguments in this file, the command-line
1261 arguments take precedence.
1262 To protect the security of your passwords, your ~/.fetchmailrc may not
1264 normally have more than 0600 (u=rw,g=,o=) permissions; fetchmail will
1265 complain and exit otherwise (this check is suppressed when --version is
1266 on).
1267 You may read the .fetchmailrc file as a list of commands to be executed
1269 when fetchmail is called with no arguments.
1270 Run Control Syntax
1272 Comments begin with a '#' and extend through the end of the line. Oth‐
1273 erwise the file consists of a series of server entries or global option
1274 statements in a free-format, token-oriented syntax.
1275 There are four kinds of tokens: grammar keywords, numbers (i.e. decimal
1277 digit sequences), unquoted strings, and quoted strings. A quoted
1278 string is bounded by double quotes and may contain whitespace (and
1279 quoted digits are treated as a string). Note that quoted strings will
1280 also contain line feed characters if they run across two or more lines,
1281 unless you use a backslash to join lines (see below). An unquoted
1282 string is any whitespace-delimited token that is neither numeric,
1283 string quoted nor contains the special characters ',', ';', ':', or
1284 '='.
1285 Any amount of whitespace separates tokens in server entries, but is
1287 otherwise ignored. You may use backslash escape sequences (\n for LF,
1288 \t for HT, \b for BS, \r for CR, \nnn for decimal (where nnn cannot
1289 start with a 0), \0ooo for octal, and \xhh for hex) to embed non-print‐
1290 able characters or string delimiters in strings. In quoted strings, a
1291 backslash at the very end of a line will cause the backslash itself and
1292 the line feed (LF or NL, new line) character to be ignored, so that you
1293 can wrap long strings. Without the backslash at the line end, the line
1294 feed character would become part of the string.
1295 Warning: while these resemble C-style escape sequences, they are not
1297 the same. fetchmail only supports these eight styles. C supports more
1298 escape sequences that consist of backslash (\) and a single character,
1299 but does not support decimal codes and does not require the leading 0
1300 in octal notation. Example: fetchmail interprets \233 the same as \xE9
1301 (Latin small letter e with acute), where C would interpret \233 as
1302 octal 0233 = \x9B (CSI, control sequence introducer).
1303 Each server entry consists of one of the keywords 'poll' or 'skip',
1305 followed by a server name, followed by server options, followed by any
1306 number of user descriptions. Note: the most common cause of syntax
1307 errors is mixing up user and server options.
1308 For backward compatibility, the word 'server' is a synonym for 'poll'.
1310 You can use the noise keywords 'and', 'with', 'has', 'wants', and
1312 'options' anywhere in an entry to make it resemble English. They're
1313 ignored, but but can make entries much easier to read at a glance. The
1314 punctuation characters ':', ';' and ',' are also ignored.
1315 Poll vs. Skip
1317 The 'poll' verb tells fetchmail to query this host when it is run with
1318 no arguments. The 'skip' verb tells fetchmail not to poll this host
1319 unless it is explicitly named on the command line. (The 'skip' verb
1320 allows you to experiment with test entries safely, or easily disable
1321 entries for hosts that are temporarily down.)
1322 Keyword/Option Summary
1324 Here are the legal options. Keyword suffixes enclosed in square brack‐
1325 ets are optional. Those corresponding to short command-line options
1326 are followed by '-' and the appropriate option letter. If option is
1327 only relevant to a single mode of operation, it is noted as 's' or 'm'
1328 for singledrop- or multidrop-mode, respectively.
1329 Here are the legal global options:
1331 Keyword Opt Mode Function
1334 ────────────────────────────────────────────────────────────────────
1335 set daemon -d Set a background poll interval in
1336 seconds.
1337 set postmaster Give the name of the last-resort
1338 mail recipient (default: user run‐
1339 ning fetchmail, "postmaster" if
1340 run by the root user)
1341 set bouncemail Direct error mail to the sender
1342 (default)
1343 set no bouncemail Direct error mail to the local
1344 postmaster (as per the 'postmas‐
1345 ter' global option above).
1346 set no spambounce Do not bounce spam-blocked mail
1347 (default).
1348 set spambounce Bounce blocked spam-blocked mail
1349 (as per the 'antispam' user
1350 option) back to the destination as
1351 indicated by the 'bouncemail'
1352 global option. Warning: Do not
1353 use this to bounce spam back to
1354 the sender - most spam is sent
1355 with false sender address and thus
1356 this option hurts innocent
1357 bystanders.
1358 set logfile -L Name of a file to append error and
1359 status messages to.
1360 set idfile -i Name of the file to store UID
1361 lists in.
1362 set syslog Do error logging through sys‐
1363 log(3).
1364 set no syslog Turn off error logging through
1365 syslog(3). (default)
1366 set properties String value that is ignored by
1367 fetchmail (may be used by exten‐
1368 sion scripts).
1369 Here are the legal server options:
1371 Keyword Opt Mode Function
1374 ─────────────────────────────────────────────────────────────────
1375 via Specify DNS name of mailserver,
1376 overriding poll name
1377 proto[col] -p Specify protocol (case insensi‐
1380 tive): POP2, POP3, IMAP, APOP,
1381 KPOP
1382 local[domains] m Specify domain(s) to be regarded
1383 as local
1384 port Specify TCP/IP service port (obso‐
1385 lete, use 'service' instead).
1386 service -P Specify service name (a numeric
1387 value is also allowed and consid‐
1388 ered a TCP/IP port number).
1389 auth[enticate] Set authentication type (default
1390 'any')
1391 timeout -t Server inactivity timeout in sec‐
1392 onds (default 300)
1393 envelope -E m Specify envelope-address header
1394 name
1395 no envelope m Disable looking for envelope
1396 address
1397 qvirtual -Q m Qmail virtual domain prefix to
1398 remove from user name
1399 aka m Specify alternate DNS names of
1400 mailserver
1401 interface -I specify IP interface(s) that must
1402 be up for server poll to take
1403 place
1404 monitor -M Specify IP address to monitor for
1405 activity
1406 plugin Specify command through which to
1407 make server connections.
1408 plugout Specify command through which to
1409 make listener connections.
1410 dns m Enable DNS lookup for multidrop
1411 (default)
1412 no dns m Disable DNS lookup for multidrop
1413 checkalias m Do comparison by IP address for
1414 multidrop
1415 no checkalias m Do comparison by name for mul‐
1416 tidrop (default)
1417 uidl -U Force POP3 to use client-side
1418 UIDLs (recommended)
1419 no uidl Turn off POP3 use of client-side
1420 UIDLs (default)
1421 interval Only check this site every N poll
1422 cycles; N is a numeric argument.
1423 tracepolls Add poll tracing information to
1424 the Received header
1425 principal Set Kerberos principal (only use‐
1426 ful with IMAP and kerberos)
1427 esmtpname Set name for RFC2554 authentica‐
1428 tion to the ESMTP server.
1429 esmtppassword Set password for RFC2554 authenti‐
1430 cation to the ESMTP server.
1431 Here are the legal user options:
1433 Keyword Opt Mode Function
1436 ───────────────────────────────────────────────────────────────────
1437 user[name] -u Set remote user name (local user
1438 name if name followed by 'here')
1439 is Connect local and remote user
1440 names
1441 to Connect local and remote user
1442 names
1443 pass[word] Specify remote account password
1444 ssl Connect to server over the speci‐
1445 fied base protocol using SSL
1446 encryption
1447 sslcert Specify file for client side pub‐
1448 lic SSL certificate
1449 sslkey Specify file for client side pri‐
1452 vate SSL key
1453 sslproto Force ssl protocol for connection
1454 folder -r Specify remote folder to query
1455 smtphost -S Specify smtp host(s) to forward to
1456 fetchdomains m Specify domains for which mail
1457 should be fetched
1458 smtpaddress -D Specify the domain to be put in
1459 RCPT TO lines
1460 smtpname Specify the user and domain to be
1461 put in RCPT TO lines
1462 antispam -Z Specify what SMTP returns are
1463 interpreted as spam-policy blocks
1464 mda -m Specify MDA for local delivery
1465 bsmtp -o Specify BSMTP batch file to append
1466 to
1467 preconnect Command to be executed before each
1468 connection
1469 postconnect Command to be executed after each
1470 connection
1471 keep -k Don't delete seen messages from
1472 server (for POP3, uidl is recom‐
1473 mended)
1474 flush -F Flush all seen messages before
1475 querying (DANGEROUS)
1476 limitflush Flush all oversized messages
1477 before querying
1478 fetchall -a Fetch all messages whether seen or
1479 not
1480 rewrite Rewrite destination addresses for
1481 reply (default)
1482 stripcr Strip carriage returns from ends
1483 of lines
1484 forcecr Force carriage returns at ends of
1485 lines
1486 pass8bits Force BODY=8BITMIME to ESMTP lis‐
1487 tener
1488 dropstatus Strip Status and X-Mozilla-Status
1489 lines out of incoming mail
1490 dropdelivered Strip Delivered-To lines out of
1491 incoming mail
1492 mimedecode Convert quoted-printable to 8-bit
1493 in MIME messages
1494 idle Idle waiting for new messages
1495 after each poll (IMAP only)
1496 no keep -K Delete seen messages from server
1497 (default)
1498 no flush Don't flush all seen messages
1499 before querying (default)
1500 no fetchall Retrieve only new messages
1501 (default)
1502 no rewrite Don't rewrite headers
1503 no stripcr Don't strip carriage returns
1504 (default)
1505 no forcecr Don't force carriage returns at
1506 EOL (default)
1507 no pass8bits Don't force BODY=8BITMIME to ESMTP
1508 listener (default)
1509 no dropstatus Don't drop Status headers
1510 (default)
1511 no dropdelivered Don't drop Delivered-To headers
1512 (default)
1513 no mimedecode Don't convert quoted-printable to
1514 8-bit in MIME messages (default)
1515 no idle Don't idle waiting for new mes‐
1516 sages after each poll (IMAP only)
1517 limit -l Set message size limit
1518 warnings -w Set message size warning interval
1519 batchlimit -b Max # messages to forward in sin‐
1520 gle connect
1521 fetchlimit -B Max # messages to fetch in single
1524 connect
1525 fetchsizelimit Max # message sizes to fetch in
1526 single transaction
1527 fastuidl Use binary search for first unseen
1528 message (POP3 only)
1529 expunge -e Perform an expunge on every #th
1530 message (IMAP and POP3 only)
1531 properties String value is ignored by fetch‐
1532 mail (may be used by extension
1533 scripts)
1534 Remember that all user options must follow all server options.
1536 In the .fetchmailrc file, the 'envelope' string argument may be pre‐
1538 ceded by a whitespace-separated number. This number, if specified, is
1539 the number of such headers to skip over (that is, an argument of 1
1540 selects the second header of the given type). This is sometime useful
1541 for ignoring bogus envelope headers created by an ISP's local delivery
1542 agent or internal forwards (through mail inspection systems, for
1543 instance).
1544 Keywords Not Corresponding To Option Switches
1546 The 'folder' and 'smtphost' options (unlike their command-line equiva‐
1547 lents) can take a space- or comma-separated list of names following
1548 them.
1549 All options correspond to the obvious command-line arguments, except
1551 the following: 'via', 'interval', 'aka', 'is', 'to', 'dns'/'no dns',
1552 'checkalias'/'no checkalias', 'password', 'preconnect', 'postconnect',
1553 'localdomains', 'stripcr'/'no stripcr', 'forcecr'/'no forcecr',
1554 'pass8bits'/'no pass8bits' 'dropstatus/no dropstatus', 'dropdeliv‐
1555 ered/no dropdelivered', 'mimedecode/no mimedecode', 'no idle', and 'no
1556 envelope'.
1557 The 'via' option is for if you want to have more than one configuration
1559 pointing at the same site. If it is present, the string argument will
1560 be taken as the actual DNS name of the mailserver host to query. This
1561 will override the argument of poll, which can then simply be a distinct
1562 label for the configuration (e.g. what you would give on the command
1563 line to explicitly query this host).
1564 The 'interval' option (which takes a numeric argument) allows you to
1566 poll a server less frequently than the basic poll interval. If you say
1567 'interval N' the server this option is attached to will only be queried
1568 every N poll intervals.
1569 Singledrop vs. Multidrop options
1571 The 'is' or 'to' keywords associate the following local (client)
1572 name(s) (or server-name to client-name mappings separated by =) with
1573 the mailserver user name in the entry. If an is/to list has '*' as its
1574 last name, unrecognized names are simply passed through. Note that
1575 until fetchmail version 6.3.4 inclusively, these lists could only con‐
1576 tain local parts of user names (fetchmail would only look at the part
1577 before the @ sign). fetchmail versions 6.3.5 and newer support full
1578 addresses on the left hand side of these mappings, and they take prece‐
1579 dence over any 'localdomains', 'aka', 'via' or similar mappings.
1580 A single local name can be used to support redirecting your mail when
1582 your username on the client machine is different from your name on the
1583 mailserver. When there is only a single local name, mail is forwarded
1584 to that local username regardless of the message's Received, To, Cc,
1585 and Bcc headers. In this case, fetchmail never does DNS lookups.
1586 When there is more than one local name (or name mapping), fetchmail
1588 looks at the envelope header, if configured, and otherwise at the
1589 Received, To, Cc, and Bcc headers of retrieved mail (this is 'multidrop
1590 mode'). It looks for addresses with hostname parts that match your
1591 poll name or your 'via', 'aka' or 'localdomains' options, and usually
1592 also for hostname parts which DNS tells it are aliases of the
1593 mailserver. See the discussion of 'dns', 'checkalias', 'localdomains',
1594 and 'aka' for details on how matching addresses are handled.
1595 If fetchmail cannot match any mailserver usernames or localdomain
1597 addresses, the mail will be bounced. Normally it will be bounced to
1598 the sender, but if the 'bouncemail' global option is off, the mail will
1599 go to the local postmaster instead. (see the 'postmaster' global
1600 option). See also BUGS.
1601 The 'dns' option (normally on) controls the way addresses from mul‐
1603 tidrop mailboxes are checked. On, it enables logic to check each host
1604 address that does not match an 'aka' or 'localdomains' declaration by
1605 looking it up with DNS. When a mailserver username is recognized
1606 attached to a matching hostname part, its local mapping is added to the
1607 list of local recipients.
1608 The 'checkalias' option (normally off) extends the lookups performed by
1610 the 'dns' keyword in multidrop mode, providing a way to cope with
1611 remote MTAs that identify themselves using their canonical name, while
1612 they're polled using an alias. When such a server is polled, checks to
1613 extract the envelope address fail, and fetchmail reverts to delivery
1614 using the To/Cc/Bcc headers (See below 'Header vs. Envelope
1615 addresses'). Specifying this option instructs fetchmail to retrieve
1616 all the IP addresses associated with both the poll name and the name
1617 used by the remote MTA and to do a comparison of the IP addresses.
1618 This comes in handy in situations where the remote server undergoes
1619 frequent canonical name changes, that would otherwise require modifica‐
1620 tions to the rcfile. 'checkalias' has no effect if 'no dns' is speci‐
1621 fied in the rcfile.
1622 The 'aka' option is for use with multidrop mailboxes. It allows you to
1624 pre-declare a list of DNS aliases for a server. This is an optimiza‐
1625 tion hack that allows you to trade space for speed. When fetchmail,
1626 while processing a multidrop mailbox, grovels through message headers
1627 looking for names of the mailserver, pre-declaring common ones can save
1628 it from having to do DNS lookups. Note: the names you give as argu‐
1629 ments to 'aka' are matched as suffixes -- if you specify (say) 'aka
1630 netaxs.com', this will match not just a hostname netaxs.com, but any
1631 hostname that ends with '.netaxs.com'; such as (say) pop3.netaxs.com
1632 and mail.netaxs.com.
1633 The 'localdomains' option allows you to declare a list of domains which
1635 fetchmail should consider local. When fetchmail is parsing address
1636 lines in multidrop modes, and a trailing segment of a host name matches
1637 a declared local domain, that address is passed through to the listener
1638 or MDA unaltered (local-name mappings are not applied).
1639 If you are using 'localdomains', you may also need to specify 'no enve‐
1641 lope', which disables fetchmail's normal attempt to deduce an envelope
1642 address from the Received line or X-Envelope-To header or whatever
1643 header has been previously set by 'envelope'. If you set 'no envelope'
1644 in the defaults entry it is possible to undo that in individual entries
1645 by using 'envelope <string>'. As a special case, 'envelope "Received"'
1646 restores the default parsing of Received lines.
1647 The password option requires a string argument, which is the password
1649 to be used with the entry's server.
1650 The 'preconnect' keyword allows you to specify a shell command to be
1652 executed just before each time fetchmail establishes a mailserver con‐
1653 nection. This may be useful if you are attempting to set up secure POP
1654 connections with the aid of ssh(1). If the command returns a nonzero
1655 status, the poll of that mailserver will be aborted.
1656 Similarly, the 'postconnect' keyword similarly allows you to specify a
1658 shell command to be executed just after each time a mailserver connec‐
1659 tion is taken down.
1660 The 'forcecr' option controls whether lines terminated by LF only are
1662 given CRLF termination before forwarding. Strictly speaking RFC821
1663 requires this, but few MTAs enforce the requirement it so this option
1664 is normally off (only one such MTA, qmail, is in significant use at
1665 time of writing).
1666 The 'stripcr' option controls whether carriage returns are stripped out
1668 of retrieved mail before it is forwarded. It is normally not necessary
1669 to set this, because it defaults to 'on' (CR stripping enabled) when
1670 there is an MDA declared but 'off' (CR stripping disabled) when for‐
1671 warding is via SMTP. If 'stripcr' and 'forcecr' are both on, 'stripcr'
1672 will override.
1673 The 'pass8bits' option exists to cope with Microsoft mail programs that
1675 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
1676 this option off (the default) and such a header present, fetchmail
1677 declares BODY=7BIT to an ESMTP-capable listener; this causes problems
1678 for messages actually using 8-bit ISO or KOI-8 character sets, which
1679 will be garbled by having the high bits of all characters stripped. If
1680 'pass8bits' is on, fetchmail is forced to declare BODY=8BITMIME to any
1681 ESMTP-capable listener. If the listener is 8-bit-clean (as all the
1682 major ones now are) the right thing will probably result.
1683 The 'dropstatus' option controls whether nonempty Status and X-Mozilla-
1685 Status lines are retained in fetched mail (the default) or discarded.
1686 Retaining them allows your MUA to see what messages (if any) were
1687 marked seen on the server. On the other hand, it can confuse some new-
1688 mail notifiers, which assume that anything with a Status line in it has
1689 been seen. (Note: the empty Status lines inserted by some buggy POP
1690 servers are unconditionally discarded.)
1691 The 'dropdelivered' option controls whether Delivered-To headers will
1693 be kept in fetched mail (the default) or discarded. These headers are
1694 added by Qmail and Postfix mailservers in order to avoid mail loops but
1695 may get in your way if you try to "mirror" a mailserver within the same
1696 domain. Use with caution.
1697 The 'mimedecode' option controls whether MIME messages using the
1699 quoted-printable encoding are automatically converted into pure 8-bit
1700 data. If you are delivering mail to an ESMTP-capable, 8-bit-clean lis‐
1701 tener (that includes all of the major MTAs like sendmail), then this
1702 will automatically convert quoted-printable message headers and data
1703 into 8-bit data, making it easier to understand when reading mail. If
1704 your e-mail programs know how to deal with MIME messages, then this
1705 option is not needed. The mimedecode option is off by default, because
1706 doing RFC2047 conversion on headers throws away character-set informa‐
1707 tion and can lead to bad results if the encoding of the headers differs
1708 from the body encoding.
1709 The 'idle' option is intended to be used with IMAP servers supporting
1711 the RFC2177 IDLE command extension, but does not strictly require it.
1712 If it is enabled, and fetchmail detects that IDLE is supported, an IDLE
1713 will be issued at the end of each poll. This will tell the IMAP server
1714 to hold the connection open and notify the client when new mail is
1715 available. If IDLE is not supported, fetchmail will simulate it by
1716 periodically issuing NOOP. If you need to poll a link frequently, IDLE
1717 can save bandwidth by eliminating TCP/IP connects and LOGIN/LOGOUT
1718 sequences. On the other hand, an IDLE connection will eat almost all of
1719 your fetchmail's time, because it will never drop the connection and
1720 allow other polls to occur unless the server times out the IDLE. It
1721 also doesn't work with multiple folders; only the first folder will
1722 ever be polled.
1723 The 'properties' option is an extension mechanism. It takes a string
1726 argument, which is ignored by fetchmail itself. The string argument
1727 may be used to store configuration information for scripts which
1728 require it. In particular, the output of '--configdump' option will
1729 make properties associated with a user entry readily available to a
1730 Python script.
1731 Miscellaneous Run Control Options
1733 The words 'here' and 'there' have useful English-like significance.
1734 Normally 'user eric is esr' would mean that mail for the remote user
1735 'eric' is to be delivered to 'esr', but you can make this clearer by
1736 saying 'user eric there is esr here', or reverse it by saying 'user esr
1737 here is eric there'
1738 Legal protocol identifiers for use with the 'protocol' keyword are:
1740 auto (or AUTO) (legacy, to be removed from future release)
1742 pop2 (or POP2) (legacy, to be removed from future release)
1743 pop3 (or POP3)
1744 sdps (or SDPS)
1745 imap (or IMAP)
1746 apop (or APOP)
1747 kpop (or KPOP)
1748 Legal authentication types are 'any', 'password', 'kerberos', 'ker‐
1751 beros_v4', 'kerberos_v5' and 'gssapi', 'cram-md5', 'otp', 'msn' (only
1752 for POP3), 'ntlm', 'ssh', 'external' (only IMAP). The 'password' type
1753 specifies authentication by normal transmission of a password (the
1754 password may be plain text or subject to protocol-specific encryption
1755 as in APOP); 'kerberos' tells fetchmail to try to get a Kerberos ticket
1756 at the start of each query instead, and send an arbitrary string as the
1757 password; and 'gssapi' tells fetchmail to use GSSAPI authentication.
1758 See the description of the 'auth' keyword for more.
1759 Specifying 'kpop' sets POP3 protocol over port 1109 with Kerberos V4
1761 authentication. These defaults may be overridden by later options.
1762 There are some global option statements: 'set logfile' followed by a
1764 string sets the same global specified by --logfile. A command-line
1765 --logfile option will override this. Note that --logfile is only effec‐
1766 tive if fetchmail detaches itself from the terminal. Also, 'set dae‐
1767 mon' sets the poll interval as --daemon does. This can be overridden
1768 by a command-line --daemon option; in particular --daemon 0 can be used
1769 to force foreground operation. The 'set postmaster' statement sets the
1770 address to which multidrop mail defaults if there are no local matches.
1771 Finally, 'set syslog' sends log messages to syslogd(8).
1772
1775 Fetchmail crashing
1776 There are various ways in that fetchmail may "crash", i. e. stop opera‐
1777 tion suddenly and unexpectedly. A "crash" usually refers to an error
1778 condition that the software did not handle by itself. A well-known
1779 failure mode is the "segmentation fault" or "signal 11" or "SIGSEGV" or
1780 just "segfault" for short. These can be caused by hardware or by soft‐
1781 ware problems. Software-induced segfaults can usually be reproduced
1782 easily and in the same place, whereas hardware-induced segfaults can go
1783 away if the computer is rebooted, or powered off for a few hours, and
1784 can happen in random locations even if you use the software the same
1785 way.
1786 For solving hardware-induced segfaults, find the faulty component and
1788 repair or replace it. <http://www.bitwizard.nl/sig11/> may help you
1789 with details.
1790 For solving software-induced segfaults, the developers may need a
1792 "stack backtrace".
1793 Enabling fetchmail core dumps
1796 By default, fetchmail suppresses core dumps as these might contain
1797 passwords and other sensitive information. For debugging fetchmail
1798 crashes, obtaining a "stack backtrace" from a core dump is often the
1799 quickest way to solve the problem, and when posting your problem on a
1800 mailing list, the developers may ask you for a "backtrace".
1801 1. To get useful backtraces, fetchmail needs to be installed without
1803 getting stripped of its compilation symbols. Unfortunately, most
1804 binary packages that are installed are stripped, and core files from
1805 symbol-stripped programs are worthless. So you may need to recompile
1806 fetchmail. On many systems, you can type
1807 file `which fetchmail`
1809 to find out if fetchmail was symbol-stripped or not. If yours was
1811 unstripped, fine, proceed, if it was stripped, you need to recompile
1812 the source code first. You do not usually need to install fetchmail in
1813 order to debug it.
1814 2. The shell environment that starts fetchmail needs to enable core
1816 dumps. The key is the "maximum core (file) size" that can usually be
1817 configured with a tool named "limit" or "ulimit". See the documentation
1818 for your shell for details. In the popular bash shell, "ulimit -Sc
1819 unlimited" will allow the core dump.
1820 3. You need to tell fetchmail, too, to allow core dumps. To do this,
1822 run fetchmail with the -d0 -v options. It is often easier to also add
1823 --nosyslog -N as well.
1824 Finally, you need to reproduce the crash. You can just start fetchmail
1826 from the directory where you compiled it by typing ./fetchmail, so the
1827 complete command line will start with ./fetchmail -Nvd0 --nosyslog and
1828 perhaps list your other options.
1829 After the crash, run your debugger to obtain the core dump. The debug‐
1831 ger will often be GNU GDB, you can then type (adjust paths as neces‐
1832 sary) gdb ./fetchmail fetchmail.core and then, after GDB has started up
1833 and read all its files, type backtrace full, save the output (copy &
1834 paste will do, the backtrace will be read by a human) and then type
1835 quit to leave gdb. Note: on some systems, the core files have differ‐
1836 ent names, they might contain a number instead of the program name, or
1837 number and name, but it will usually have "core" as part of their name.
1838
1841 When trying to determine the originating address of a message, fetch‐
1842 mail looks through headers in the following order:
1843 Return-Path:
1845 Resent-Sender: (ignored if it doesn't contain an @ or !)
1846 Sender: (ignored if it doesn't contain an @ or !)
1847 Resent-From:
1848 From:
1849 Reply-To:
1850 Apparently-From:
1851 The originating address is used for logging, and to set the MAIL FROM
1853 address when forwarding to SMTP. This order is intended to cope grace‐
1854 fully with receiving mailing list messages in multidrop mode. The
1855 intent is that if a local address doesn't exist, the bounce message
1856 won't be returned blindly to the author or to the list itself, but
1857 rather to the list manager (which is less annoying).
1858 In multidrop mode, destination headers are processed as follows: First,
1860 fetchmail looks for the Received: header (or whichever one is specified
1861 by the 'envelope' option) to determine the local recipient address. If
1862 the mail is addressed to more than one recipient, the Received line
1863 won't contain any information regarding recipient addresses.
1864 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
1866 lines. If they exist, they should contain the final recipients and
1867 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent-*
1868 lines don't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
1869 looked for. (The presence of a Resent-To: is taken to imply that the
1870 person referred by the To: address has already received the original
1871 copy of the mail.)
1872
1875 Note that although there are password declarations in a good many of
1876 the examples below, this is mainly for illustrative purposes. We rec‐
1877 ommend stashing account/password pairs in your $HOME/.netrc file, where
1878 they can be used not just by fetchmail but by ftp(1) and other pro‐
1879 grams.
1880 Basic format is:
1882 poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD
1884 Example:
1886 poll pop.provider.net protocol pop3 username "jsmith" password "secret1"
1888 Or, using some abbreviations:
1890 poll pop.provider.net proto pop3 user "jsmith" password "secret1"
1892 Multiple servers may be listed:
1894 poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
1896 poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"
1897 Here's a version of those two with more whitespace and some noise
1899 words:
1900 poll pop.provider.net proto pop3
1902 user "jsmith", with password secret1, is "jsmith" here;
1903 poll other.provider.net proto pop2:
1904 user "John.Smith", with password "My^Hat", is "John.Smith" here;
1905 This version is much easier to read and doesn't cost significantly more
1907 (parsing is done only once, at startup time).
1908 If you need to include whitespace in a parameter string, enclose the
1911 string in double quotes. Thus:
1912 poll mail.provider.net with proto pop3:
1914 user "jsmith" there has password "u can't krak this"
1915 is jws here and wants mda "/bin/mail"
1916 You may have an initial server description headed by the keyword
1918 'defaults' instead of 'poll' followed by a name. Such a record is
1919 interpreted as defaults for all queries to use. It may be overwritten
1920 by individual server descriptions. So, you could write:
1921 defaults proto pop3
1923 user "jsmith"
1924 poll pop.provider.net
1925 pass "secret1"
1926 poll mail.provider.net
1927 user "jjsmith" there has password "secret2"
1928 It's possible to specify more than one user per server (this is only
1930 likely to be useful when running fetchmail in daemon mode as root).
1931 The 'user' keyword leads off a user description, and every user speci‐
1932 fication in a multi-user entry must include it. Here's an example:
1933 poll pop.provider.net proto pop3 port 3111
1935 user "jsmith" with pass "secret1" is "smith" here
1936 user jones with pass "secret2" is "jjones" here keep
1937 This associates the local username 'smith' with the pop.provider.net
1939 username 'jsmith' and the local username 'jjones' with the
1940 pop.provider.net username 'jones'. Mail for 'jones' is kept on the
1941 server after download.
1942 Here's what a simple retrieval configuration for a multidrop mailbox
1944 looks like:
1945 poll pop.provider.net:
1947 user maildrop with pass secret1 to golux 'hurkle'='happy' snark here
1948 This says that the mailbox of account 'maildrop' on the server is a
1950 multidrop box, and that messages in it should be parsed for the server
1951 user names 'golux', 'hurkle', and 'snark'. It further specifies that
1952 'golux' and 'snark' have the same name on the client as on the server,
1953 but mail for server user 'hurkle' should be delivered to client user
1954 'happy'.
1955 Note that fetchmail, until version 6.3.4, did NOT allow full
1957 user@domain specifications here, these would never match. Fetchmail
1958 6.3.5 and newer support user@domain specifications on the left-hand
1959 side of a user mapping.
1960 Here's an example of another kind of multidrop connection:
1962 poll pop.provider.net localdomains loonytoons.org toons.org:
1964 user maildrop with pass secret1 to * here
1965 This also says that the mailbox of account 'maildrop' on the server is
1967 a multidrop box. It tells fetchmail that any address in the loony‐
1968 toons.org or toons.org domains (including sub-domain addresses like
1969 'joe@daffy.loonytoons.org') should be passed through to the local SMTP
1970 listener without modification. Be careful of mail loops if you do
1971 this!
1972 Here's an example configuration using ssh and the plugin option. The
1974 queries are made directly on the stdin and stdout of imapd via ssh.
1975 Note that in this setup, IMAP authentication can be skipped.
1976 poll mailhost.net with proto imap:
1978 plugin "ssh %h /usr/sbin/imapd" auth ssh;
1979 user esr is esr here
1980
1983 Use the multiple-local-recipients feature with caution -- it can bite.
1984 All multidrop features are ineffective in ETRN and ODMR modes.
1985 Also, note that in multidrop mode duplicate mails are suppressed. A
1987 piece of mail is considered duplicate if it has the same message-ID as
1988 the message immediately preceding and more than one addressee. Such
1989 runs of messages may be generated when copies of a message addressed to
1990 multiple users are delivered to a multidrop box.
1991 Header vs. Envelope addresses
1994 The fundamental problem is that by having your mailserver toss several
1995 peoples' mail in a single maildrop box, you may have thrown away poten‐
1996 tially vital information about who each piece of mail was actually
1997 addressed to (the 'envelope address', as opposed to the header
1998 addresses in the RFC822 To/Cc headers - the Bcc is not available at the
1999 receiving end). This 'envelope address' is the address you need in
2000 order to reroute mail properly.
2001 Sometimes fetchmail can deduce the envelope address. If the mailserver
2003 MTA is sendmail and the item of mail had just one recipient, the MTA
2004 will have written a 'by/for' clause that gives the envelope addressee
2005 into its Received header. But this doesn't work reliably for other
2006 MTAs, nor if there is more than one recipient. By default, fetchmail
2007 looks for envelope addresses in these lines; you can restore this
2008 default with -E "Received" or 'envelope Received'.
2009 As a better alternative, some SMTP listeners and/or mail servers insert
2011 a header in each message containing a copy of the envelope addresses.
2012 This header (when it exists) is often 'X-Original-To', 'Delivered-To'
2013 or 'X-Envelope-To'. Fetchmail's assumption about this can be changed
2014 with the -E or 'envelope' option. Note that writing an envelope header
2015 of this kind exposes the names of recipients (including blind-copy
2016 recipients) to all receivers of the messages, so the upstream must
2017 store one copy of the message per recipient to avoid becoming a privacy
2018 problem.
2019 Postfix, since version 2.0, writes an X-Original-To: header which con‐
2021 tains a copy of the envelope as it was received.
2022 Qmail and Postfix generally write a 'Delivered-To' header upon deliver‐
2024 ing the message to the mail spool and use it to avoid mail loops.
2025 Qmail virtual domains however will prefix the user name with a string
2026 that normally matches the user's domain. To remove this prefix you can
2027 use the -Q or 'qvirtual' option.
2028 Sometimes, unfortunately, neither of these methods works. That is the
2030 point when you should contact your ISP and ask them to provide such an
2031 envelope header, and you should not use multidrop in this situation.
2032 When they all fail, fetchmail must fall back on the contents of To/Cc
2033 headers (Bcc headers are not available - see below) to try to determine
2034 recipient addressees -- and these are unreliable. In particular, mail‐
2035 ing-list software often ships mail with only the list broadcast address
2036 in the To header.
2037 Note that a future version of fetchmail may remove To/Cc parsing!
2039 When fetchmail cannot deduce a recipient address that is local, and the
2041 intended recipient address was anyone other than fetchmail's invoking
2042 user, mail will get lost. This is what makes the multidrop feature
2043 risky without proper envelope information.
2044 A related problem is that when you blind-copy a mail message, the Bcc
2046 information is carried only as envelope address (it's removed from the
2047 headers by the sending mail server, so fetchmail can see it only if
2048 there is an X-0elope-To header). Thus, blind-copying to someone who
2049 gets mail over a fetchmail multidrop link will fail unless the the
2050 mailserver host routinely writes X-Envelope-To or an equivalent header
2051 into messages in your maildrop.
2052 In conclusion, mailing lists and Bcc'd mail can only work if the server
2054 you're fetching from (1) stores one copy of the message per recipient
2055 in your domain and (2) records the envelope information in a special
2056 header (X-Original-To, Delivered-To, X-Envelope-To).
2057 Good Ways To Use Multidrop Mailboxes
2060 Multiple local names can be used to administer a mailing list from the
2061 client side of a fetchmail collection. Suppose your name is 'esr', and
2062 you want to both pick up your own mail and maintain a mailing list
2063 called (say) "fetchmail-friends", and you want to keep the alias list
2064 on your client machine.
2065 On your server, you can alias 'fetchmail-friends' to 'esr'; then, in
2067 your .fetchmailrc, declare 'to esr fetchmail-friends here'. Then, when
2068 mail including 'fetchmail-friends' as a local address gets fetched, the
2069 list name will be appended to the list of recipients your SMTP listener
2070 sees. Therefore it will undergo alias expansion locally. Be sure to
2071 include 'esr' in the local alias expansion of fetchmail-friends, or
2072 you'll never see mail sent only to the list. Also be sure that your
2073 listener has the "me-too" option set (sendmail's -oXm command-line
2074 option or OXm declaration) so your name isn't removed from alias expan‐
2075 sions in messages you send.
2076 This trick is not without its problems, however. You'll begin to see
2078 this when a message comes in that is addressed only to a mailing list
2079 you do not have declared as a local name. Each such message will fea‐
2080 ture an 'X-Fetchmail-Warning' header which is generated because fetch‐
2081 mail cannot find a valid local name in the recipient addresses. Such
2082 messages default (as was described above) to being sent to the local
2083 user running fetchmail, but the program has no way to know that that's
2084 actually the right thing.
2085 Bad Ways To Abuse Multidrop Mailboxes
2088 Multidrop mailboxes and fetchmail serving multiple users in daemon mode
2089 do not mix. The problem, again, is mail from mailing lists, which typ‐
2090 ically does not have an individual recipient address on it. Unless
2091 fetchmail can deduce an envelope address, such mail will only go to the
2092 account running fetchmail (probably root). Also, blind-copied users
2093 are very likely never to see their mail at all.
2094 If you're tempted to use fetchmail to retrieve mail for multiple users
2096 from a single mail drop via POP or IMAP, think again (and reread the
2097 section on header and envelope addresses above). It would be smarter
2098 to just let the mail sit in the mailserver's queue and use fetchmail's
2099 ETRN or ODMR modes to trigger SMTP sends periodically (of course, this
2100 means you have to poll more frequently than the mailserver's expiry
2101 period). If you can't arrange this, try setting up a UUCP feed.
2102 If you absolutely must use multidrop for this purpose, make sure your
2104 mailserver writes an envelope-address header that fetchmail can see.
2105 Otherwise you will lose mail and it will come back to haunt you.
2106 Speeding Up Multidrop Checking
2109 Normally, when multiple users are declared fetchmail extracts recipient
2110 addresses as described above and checks each host part with DNS to see
2111 if it's an alias of the mailserver. If so, the name mappings described
2112 in the "to ... here" declaration are done and the mail locally deliv‐
2113 ered.
2114 This is a convenient but also slow method. To speed it up, pre-declare
2116 mailserver aliases with 'aka'; these are checked before DNS lookups are
2117 done. If you're certain your aka list contains all DNS aliases of the
2118 mailserver (and all MX names pointing at it - note this may change in a
2119 future version) you can declare 'no dns' to suppress DNS lookups
2120 entirely and only match against the aka list.
2121
2124 To facilitate the use of fetchmail in shell scripts, an exit status
2125 code is returned to give an indication of what occurred during a given
2126 connection.
2127 The exit codes returned by fetchmail are as follows:
2129 0 One or more messages were successfully retrieved (or, if the -c
2131 option was selected, were found waiting but not retrieved).
2132 1 There was no mail awaiting retrieval. (There may have been old
2134 mail still on the server but not selected for retrieval.)
2135 2 An error was encountered when attempting to open a socket to
2137 retrieve mail. If you don't know what a socket is, don't worry
2138 about it -- just treat this as an 'unrecoverable error'. This
2139 error can also be because a protocol fetchmail wants to use is
2140 not listed in /etc/services.
2141 3 The user authentication step failed. This usually means that a
2143 bad user-id, password, or APOP id was specified. Or it may mean
2144 that you tried to run fetchmail under circumstances where it did
2145 not have standard input attached to a terminal and could not
2146 prompt for a missing password.
2147 4 Some sort of fatal protocol error was detected.
2149 5 There was a syntax error in the arguments to fetchmail.
2151 6 The run control file had bad permissions.
2153 7 There was an error condition reported by the server. Can also
2155 fire if fetchmail timed out while waiting for the server.
2156 8 Client-side exclusion error. This means fetchmail either found
2158 another copy of itself already running, or failed in such a way
2159 that it isn't sure whether another copy is running.
2160 9 The user authentication step failed because the server responded
2162 "lock busy". Try again after a brief pause! This error is not
2163 implemented for all protocols, nor for all servers. If not
2164 implemented for your server, "3" will be returned instead, see
2165 above. May be returned when talking to qpopper or other servers
2166 that can respond with "lock busy" or some similar text contain‐
2167 ing the word "lock".
2168 10 The fetchmail run failed while trying to do an SMTP port open or
2170 transaction.
2171 11 Fatal DNS error. Fetchmail encountered an error while perform‐
2173 ing a DNS lookup at startup and could not proceed.
2174 12 BSMTP batch file could not be opened.
2176 13 Poll terminated by a fetch limit (see the --fetchlimit option).
2178 14 Server busy indication.
2180 23 Internal error. You should see a message on standard error with
2182 details.
2183 24 These are internal codes and should not appear externally.
2185 When fetchmail queries more than one host, return status is 0 if any
2187 query successfully retrieved mail. Otherwise the returned error status
2188 is that of the last host queried.
2189
2192 ~/.fetchmailrc
2193 default run control file
2194 ~/.fetchids
2196 default location of file associating hosts with last message IDs
2197 seen (used only with newer RFC1939-compliant POP3 servers support‐
2198 ing the UIDL command).
2199 ~/.fetchmail.pid
2201 lock file to help prevent concurrent runs (non-root mode).
2202 ~/.netrc
2204 your FTP run control file, which (if present) will be searched for
2205 passwords as a last resort before prompting for one interactively.
2206 /var/run/fetchmail.pid
2208 lock file to help prevent concurrent runs (root mode, Linux sys‐
2209 tems).
2210 /etc/fetchmail.pid
2212 lock file to help prevent concurrent runs (root mode, systems
2213 without /var/run).
2214
2217 If the FETCHMAILUSER variable is set, it is used as the name of the
2218 calling user (default local name) for purposes such as mailing error
2219 notifications. Otherwise, if either the LOGNAME or USER variable is
2220 correctly set (e.g. the corresponding UID matches the session user ID)
2221 then that name is used as the default local name. Otherwise getp‐
2222 wuid(3) must be able to retrieve a password entry for the session ID
2223 (this elaborate logic is designed to handle the case of multiple names
2224 per userid gracefully).
2225 If the environment variable FETCHMAILHOME is set to a valid and exist‐
2227 ing directory name, fetchmail will read $FETCHMAILHOME/fetchmailrc (the
2228 dot is missing in this case), $FETCHMAILHOME/.fetchids and $FETCHMAIL‐
2229 HOME/.fetchmail.pid rather than from the user's home directory. The
2230 .netrc file is always looked for in the the invoking user's home direc‐
2231 tory regardless of FETCHMAILHOME's setting.
2232 If the HOME_ETC variable is set, fetchmail will read $HOME_ETC/.fetch‐
2234 mailrc instead of ~/.fetchmailrc.
2235 If HOME_ETC and FETCHMAILHOME are set, HOME_ETC will be ignored.
2237
2240 If a fetchmail daemon is running as root, SIGUSR1 wakes it up from its
2241 sleep phase and forces a poll of all non-skipped servers. For compati‐
2242 bility reasons, SIGHUP can also be used in 6.3.X but may not be avail‐
2243 able in future fetchmail versions.
2244 If fetchmail is running in daemon mode as non-root, use SIGUSR1 to wake
2246 it (this is so SIGHUP due to logout can retain the default action of
2247 killing it).
2248 Running fetchmail in foreground while a background fetchmail is running
2250 will do whichever of these is appropriate to wake it up.
2251
2254 Fetchmail cannot handle user names that contain blanks after a "@"
2255 character, for instance "demonstr@ti on". These are rather uncommon and
2256 only hurt when using UID-based --keep setups, so the 6.3.X versions of
2257 fetchmail won't be fixed.
2258 Please check the NEWS file that shipped with fetchmail for more known
2260 bugs than those listed here.
2261 The assumptions that the DNS and in particular the checkalias options
2263 make are not often sustainable. For instance, it has become uncommon
2264 for an MX server to be a POP3 or IMAP server at the same time. There‐
2265 fore the MX lookups may go away in a future release.
2266 The mda and plugin options interact badly. In order to collect error
2268 status from the MDA, fetchmail has to change its normal signal handling
2269 so that dead plugin processes don't get reaped until the end of the
2270 poll cycle. This can cause resource starvation if too many zombies
2271 accumulate. So either don't deliver to a MDA using plugins or risk
2272 being overrun by an army of undead.
2273 The --interface option does not support IPv6 and it is doubtful if it
2275 ever will, since there is no portable way to query interface IPv6
2276 addresses.
2277 The RFC822 address parser used in multidrop mode chokes on some
2279 @-addresses that are technically legal but bizarre. Strange uses of
2280 quoting and embedded comments are likely to confuse it.
2281 In a message with multiple envelope headers, only the last one pro‐
2283 cessed will be visible to fetchmail.
2284 Use of some of these protocols requires that the program send unen‐
2286 crypted passwords over the TCP/IP connection to the mailserver. This
2287 creates a risk that name/password pairs might be snaffled with a packet
2288 sniffer or more sophisticated monitoring software. Under Linux and
2289 FreeBSD, the --interface option can be used to restrict polling to
2290 availability of a specific interface device with a specific local or
2291 remote IP address, but snooping is still possible if (a) either host
2292 has a network device that can be opened in promiscuous mode, or (b) the
2293 intervening network link can be tapped. We recommend the use of ssh(1)
2294 tunnelling to not only shroud your passwords but encrypt the entire
2295 conversation.
2296 Use of the %F or %T escapes in an mda option could open a security
2298 hole, because they pass text manipulable by an attacker to a shell com‐
2299 mand. Potential shell characters are replaced by '_' before execution.
2300 The hole is further reduced by the fact that fetchmail temporarily dis‐
2301 cards any suid privileges it may have while running the MDA. For maxi‐
2302 mum safety, however, don't use an mda command containing %F or %T when
2303 fetchmail is run from the root account itself.
2304 Fetchmail's method of sending bounces due to errors or spam-blocking
2306 and spam bounces requires that port 25 of localhost be available for
2307 sending mail via SMTP.
2308 If you modify a ~/.fetchmailrc while a background instance is running
2310 and break the syntax, the background instance will die silently.
2311 Unfortunately, it can't die noisily because we don't yet know whether
2312 syslog should be enabled. On some systems, fetchmail dies quietly even
2313 if there is no syntax error; this seems to have something to do with
2314 buggy terminal ioctl code in the kernel.
2315 The -f - option (reading a configuration from stdin) is incompatible
2317 with the plugin option.
2318 The 'principal' option only handles Kerberos IV, not V.
2320 Interactively entered passwords are truncated after 63 characters. If
2322 you really need to use a longer password, you will have to use a con‐
2323 figuration file.
2324 A backslash as the last character of a configuration file will be
2326 flagged as a syntax error rather than ignored.
2327 Send comments, bug reports, gripes, and the like to the fetchmail-devel
2329 list <fetchmail-devel@lists.berlios.de>. An HTML FAQ is available at
2330 the fetchmail home page; surf to http://fetchmail.berlios.de/ or do a
2331 WWW search for pages with 'fetchmail' in their titles.
2332
2335 Fetchmail is currently maintained by Matthias Andree and Rob Funk with
2336 major assistance from Sunil Shetye (for code) and Rob MacGregor (for
2337 the mailing lists).
2338 Most of the code is from Eric S. Raymond <esr@snark.thyrsus.com>. Too
2340 many other people to name here have contributed code and patches.
2341 This program is descended from and replaces popclient, by Carl Harris
2343 <ceharris@mal.com>; the internals have become quite different, but some
2344 of its interface design is directly traceable to that ancestral pro‐
2345 gram.
2346 This manual page has been improved by R. Hannes Beinert and Héctor
2348 García.
2349
2352 mutt(1), elm(1), mail(1), sendmail(8), popd(8), imapd(8), netrc(5)
2353 The fetchmail home page: <http://fetchmail.berlios.de/>
2355 The maildrop home page: <http://www.courier-mta.org/maildrop/>
2357
2359 Note that this list is just a collection of references and not a state‐
2360 ment as to the actual protocol conformance or requirements in fetch‐
2361 mail.
2362 SMTP/ESMTP:
2364 RFC 821, RFC 2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC
2365 1985, RFC 2554.
2366 mail:
2368 RFC 822, RFC 2822, RFC 1123, RFC 1892, RFC 1894.
2369 POP2:
2371 RFC 937
2372 POP3:
2374 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC 1734, RFC 1939, RFC
2375 1957, RFC 2195, RFC 2449.
2376 APOP:
2378 RFC 1460, RFC 1725, RFC 1939.
2379 RPOP:
2381 RFC 1081, RFC 1225.
2382 IMAP2/IMAP2BIS:
2384 RFC 1176, RFC 1732.
2385 IMAP4/IMAP4rev1:
2387 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC
2388 2177, RFC 2683.
2389 ETRN:
2391 RFC 1985.
2392 ODMR/ATRN:
2394 RFC 2645.
2395 OTP: RFC 1938.
2397 LMTP:
2399 RFC 2033.
2400 GSSAPI:
2402 RFC 1508.
2403 TLS: RFC 2595.
2405fetchmail fetchmail 6.3.7 fetchmail(1)