1SMTPD(8) System Manager's Manual SMTPD(8)
2
6 smtpd - Postfix SMTP server
7
9 smtpd [generic Postfix daemon options]
10 sendmail -bs
12
14 The SMTP server accepts network connection requests and performs zero
15 or more SMTP transactions per connection. Each received message is
16 piped through the cleanup(8) daemon, and is placed into the incoming
17 queue as one single queue file. For this mode of operation, the pro‐
18 gram expects to be run from the master(8) process manager.
19 Alternatively, the SMTP server be can run in stand-alone mode; this is
21 traditionally obtained with "sendmail -bs". When the SMTP server runs
22 stand-alone with non $mail_owner privileges, it receives mail even
23 while the mail system is not running, deposits messages directly into
24 the maildrop queue, and disables the SMTP server's access policies. As
25 of Postfix version 2.3, the SMTP server refuses to receive mail from
26 the network when it runs with non $mail_owner privileges.
27 The SMTP server implements a variety of policies for connection re‐
29 quests, and for parameters given to HELO, ETRN, MAIL FROM, VRFY and
30 RCPT TO commands. They are detailed below and in the main.cf configura‐
31 tion file.
32
34 The SMTP server is moderately security-sensitive. It talks to SMTP
35 clients and to DNS servers on the network. The SMTP server can be run
36 chrooted at fixed low privilege.
37
39 RFC 821 (SMTP protocol)
40 RFC 1123 (Host requirements)
41 RFC 1652 (8bit-MIME transport)
42 RFC 1869 (SMTP service extensions)
43 RFC 1870 (Message size declaration)
44 RFC 1985 (ETRN command)
45 RFC 2034 (SMTP enhanced status codes)
46 RFC 2554 (AUTH command)
47 RFC 2821 (SMTP protocol)
48 RFC 2920 (SMTP pipelining)
49 RFC 3030 (CHUNKING without BINARYMIME)
50 RFC 3207 (STARTTLS command)
51 RFC 3461 (SMTP DSN extension)
52 RFC 3463 (Enhanced status codes)
53 RFC 3848 (ESMTP transmission types)
54 RFC 4409 (Message submission)
55 RFC 4954 (AUTH command)
56 RFC 5321 (SMTP protocol)
57 RFC 6531 (Internationalized SMTP)
58 RFC 6533 (Internationalized Delivery Status Notifications)
59 RFC 7505 ("Null MX" No Service Resource Record)
60
62 Problems and transactions are logged to syslogd(8) or postlogd(8).
63 Depending on the setting of the notify_classes parameter, the postmas‐
65 ter is notified of bounces, protocol problems, policy violations, and
66 of other trouble.
67
69 Changes to main.cf are picked up automatically, as smtpd(8) processes
70 run for only a limited amount of time. Use the command "postfix reload"
71 to speed up a change.
72 The text below provides only a parameter summary. See postconf(5) for
74 more details including examples.
75
77 The following parameters work around implementation errors in other
78 software, and/or allow you to override standards in order to prevent
79 undesirable use.
80 broken_sasl_auth_clients (no)
82 Enable interoperability with remote SMTP clients that implement
83 an obsolete version of the AUTH command (RFC 4954).
84 disable_vrfy_command (no)
86 Disable the SMTP VRFY command.
87 smtpd_noop_commands (empty)
89 List of commands that the Postfix SMTP server replies to with
90 "250 Ok", without doing any syntax checks and without changing
91 state.
92 strict_rfc821_envelopes (no)
94 Require that addresses received in SMTP MAIL FROM and RCPT TO
95 commands are enclosed with <>, and that those addresses do not
96 contain RFC 822 style comments or phrases.
97 Available in Postfix version 2.1 and later:
99 smtpd_reject_unlisted_sender (no)
101 Request that the Postfix SMTP server rejects mail from unknown
102 sender addresses, even when no explicit reject_unlisted_sender
103 access restriction is specified.
104 smtpd_sasl_exceptions_networks (empty)
106 What remote SMTP clients the Postfix SMTP server will not offer
107 AUTH support to.
108 Available in Postfix version 2.2 and later:
110 smtpd_discard_ehlo_keyword_address_maps (empty)
112 Lookup tables, indexed by the remote SMTP client address, with
113 case insensitive lists of EHLO keywords (pipelining, starttls,
114 auth, etc.) that the Postfix SMTP server will not send in the
115 EHLO response to a remote SMTP client.
116 smtpd_discard_ehlo_keywords (empty)
118 A case insensitive list of EHLO keywords (pipelining, starttls,
119 auth, etc.) that the Postfix SMTP server will not send in the
120 EHLO response to a remote SMTP client.
121 smtpd_delay_open_until_valid_rcpt (yes)
123 Postpone the start of an SMTP mail transaction until a valid
124 RCPT TO command is received.
125 Available in Postfix version 2.3 and later:
127 smtpd_tls_always_issue_session_ids (yes)
129 Force the Postfix SMTP server to issue a TLS session id, even
130 when TLS session caching is turned off (smtpd_tls_ses‐
131 sion_cache_database is empty).
132 Available in Postfix version 2.6 and later:
134 tcp_windowsize (0)
136 An optional workaround for routers that break TCP window scal‐
137 ing.
138 Available in Postfix version 2.7 and later:
140 smtpd_command_filter (empty)
142 A mechanism to transform commands from remote SMTP clients.
143 Available in Postfix version 2.9 - 3.6:
145 smtpd_per_record_deadline (normal: no, overload: yes)
147 Change the behavior of the smtpd_timeout and smtpd_start‐
148 tls_timeout time limits, from a time limit per read or write
149 system call, to a time limit to send or receive a complete
150 record (an SMTP command line, SMTP response line, SMTP message
151 content line, or TLS protocol message).
152 Available in Postfix version 3.0 and later:
154 smtpd_dns_reply_filter (empty)
156 Optional filter for Postfix SMTP server DNS lookup results.
157 Available in Postfix version 3.6 and later:
159 smtpd_relay_before_recipient_restrictions (see 'postconf -d' output)
161 Evaluate smtpd_relay_restrictions before smtpd_recipient_re‐
162 strictions.
163 known_tcp_ports (lmtp=24, smtp=25, smtps=submissions=465, submis‐
165 sion=587)
166 Optional setting that avoids lookups in the services(5) data‐
167 base.
168 Available in Postfix version 3.7 and later:
170 smtpd_per_request_deadline (normal: no, overload: yes)
172 Change the behavior of the smtpd_timeout and smtpd_start‐
173 tls_timeout time limits, from a time limit per plaintext or TLS
174 read or write call, to a combined time limit for receiving a
175 complete SMTP request and for sending a complete SMTP response.
176 smtpd_min_data_rate (500)
178 The minimum plaintext data transfer rate in bytes/second for
179 DATA and BDAT requests, when deadlines are enabled with
180 smtpd_per_request_deadline.
181
183 See the ADDRESS_REWRITING_README document for a detailed discussion of
184 Postfix address rewriting.
185 receive_override_options (empty)
187 Enable or disable recipient validation, built-in content filter‐
188 ing, or address mapping.
189 Available in Postfix version 2.2 and later:
191 local_header_rewrite_clients (permit_inet_interfaces)
193 Rewrite message header addresses in mail from these clients and
194 update incomplete addresses with the domain name in $myorigin or
195 $mydomain; either don't rewrite message headers from other
196 clients at all, or rewrite message headers and update incomplete
197 addresses with the domain specified in the remote_header_re‐
198 write_domain parameter.
199
201 Available in Postfix version 2.10 and later:
202 smtpd_upstream_proxy_protocol (empty)
204 The name of the proxy protocol used by an optional before-smtpd
205 proxy agent.
206 smtpd_upstream_proxy_timeout (5s)
208 The time limit for the proxy protocol specified with the
209 smtpd_upstream_proxy_protocol parameter.
210
212 As of version 1.0, Postfix can be configured to send new mail to an ex‐
213 ternal content filter AFTER the mail is queued. This content filter is
214 expected to inject mail back into a (Postfix or other) MTA for further
215 delivery. See the FILTER_README document for details.
216 content_filter (empty)
218 After the message is queued, send the entire message to the
219 specified transport:destination.
220
222 As of version 2.1, the Postfix SMTP server can be configured to send
223 incoming mail to a real-time SMTP-based content filter BEFORE mail is
224 queued. This content filter is expected to inject mail back into Post‐
225 fix. See the SMTPD_PROXY_README document for details on how to config‐
226 ure and operate this feature.
227 smtpd_proxy_filter (empty)
229 The hostname and TCP port of the mail filtering proxy server.
230 smtpd_proxy_ehlo ($myhostname)
232 How the Postfix SMTP server announces itself to the proxy fil‐
233 ter.
234 smtpd_proxy_options (empty)
236 List of options that control how the Postfix SMTP server commu‐
237 nicates with a before-queue content filter.
238 smtpd_proxy_timeout (100s)
240 The time limit for connecting to a proxy filter and for sending
241 or receiving information.
242
244 As of version 2.3, Postfix supports the Sendmail version 8 Milter (mail
245 filter) protocol. These content filters run outside Postfix. They can
246 inspect the SMTP command stream and the message content, and can re‐
247 quest modifications before mail is queued. For details see the MIL‐
248 TER_README document.
249 smtpd_milters (empty)
251 A list of Milter (mail filter) applications for new mail that
252 arrives via the Postfix smtpd(8) server.
253 milter_protocol (6)
255 The mail filter protocol version and optional protocol exten‐
256 sions for communication with a Milter application; prior to
257 Postfix 2.6 the default protocol is 2.
258 milter_default_action (tempfail)
260 The default action when a Milter (mail filter) response is un‐
261 available (for example, bad Postfix configuration or Milter
262 failure).
263 milter_macro_daemon_name ($myhostname)
265 The {daemon_name} macro value for Milter (mail filter) applica‐
266 tions.
267 milter_macro_v ($mail_name $mail_version)
269 The {v} macro value for Milter (mail filter) applications.
270 milter_connect_timeout (30s)
272 The time limit for connecting to a Milter (mail filter) applica‐
273 tion, and for negotiating protocol options.
274 milter_command_timeout (30s)
276 The time limit for sending an SMTP command to a Milter (mail
277 filter) application, and for receiving the response.
278 milter_content_timeout (300s)
280 The time limit for sending message content to a Milter (mail
281 filter) application, and for receiving the response.
282 milter_connect_macros (see 'postconf -d' output)
284 The macros that are sent to Milter (mail filter) applications
285 after completion of an SMTP connection.
286 milter_helo_macros (see 'postconf -d' output)
288 The macros that are sent to Milter (mail filter) applications
289 after the SMTP HELO or EHLO command.
290 milter_mail_macros (see 'postconf -d' output)
292 The macros that are sent to Milter (mail filter) applications
293 after the SMTP MAIL FROM command.
294 milter_rcpt_macros (see 'postconf -d' output)
296 The macros that are sent to Milter (mail filter) applications
297 after the SMTP RCPT TO command.
298 milter_data_macros (see 'postconf -d' output)
300 The macros that are sent to version 4 or higher Milter (mail
301 filter) applications after the SMTP DATA command.
302 milter_unknown_command_macros (see 'postconf -d' output)
304 The macros that are sent to version 3 or higher Milter (mail
305 filter) applications after an unknown SMTP command.
306 milter_end_of_header_macros (see 'postconf -d' output)
308 The macros that are sent to Milter (mail filter) applications
309 after the end of the message header.
310 milter_end_of_data_macros (see 'postconf -d' output)
312 The macros that are sent to Milter (mail filter) applications
313 after the message end-of-data.
314 Available in Postfix version 3.1 and later:
316 milter_macro_defaults (empty)
318 Optional list of name=value pairs that specify default values
319 for arbitrary macros that Postfix may send to Milter applica‐
320 tions.
321 Available in Postfix version 3.2 and later:
323 smtpd_milter_maps (empty)
325 Lookup tables with Milter settings per remote SMTP client IP ad‐
326 dress.
327
329 The following parameters are applicable for both built-in and external
330 content filters.
331 Available in Postfix version 2.1 and later:
333 receive_override_options (empty)
335 Enable or disable recipient validation, built-in content filter‐
336 ing, or address mapping.
337
339 The following parameters are applicable for both before-queue and af‐
340 ter-queue content filtering.
341 Available in Postfix version 2.1 and later:
343 smtpd_authorized_xforward_hosts (empty)
345 What remote SMTP clients are allowed to use the XFORWARD fea‐
346 ture.
347
349 Postfix SASL support (RFC 4954) can be used to authenticate remote SMTP
350 clients to the Postfix SMTP server, and to authenticate the Postfix
351 SMTP client to a remote SMTP server. See the SASL_README document for
352 details.
353 broken_sasl_auth_clients (no)
355 Enable interoperability with remote SMTP clients that implement
356 an obsolete version of the AUTH command (RFC 4954).
357 smtpd_sasl_auth_enable (no)
359 Enable SASL authentication in the Postfix SMTP server.
360 smtpd_sasl_local_domain (empty)
362 The name of the Postfix SMTP server's local SASL authentication
363 realm.
364 smtpd_sasl_security_options (noanonymous)
366 Postfix SMTP server SASL security options; as of Postfix 2.3 the
367 list of available features depends on the SASL server implemen‐
368 tation that is selected with smtpd_sasl_type.
369 smtpd_sender_login_maps (empty)
371 Optional lookup table with the SASL login names that own the
372 sender (MAIL FROM) addresses.
373 Available in Postfix version 2.1 and later:
375 smtpd_sasl_exceptions_networks (empty)
377 What remote SMTP clients the Postfix SMTP server will not offer
378 AUTH support to.
379 Available in Postfix version 2.1 and 2.2:
381 smtpd_sasl_application_name (smtpd)
383 The application name that the Postfix SMTP server uses for SASL
384 server initialization.
385 Available in Postfix version 2.3 and later:
387 smtpd_sasl_authenticated_header (no)
389 Report the SASL authenticated user name in the smtpd(8) Received
390 message header.
391 smtpd_sasl_path (smtpd)
393 Implementation-specific information that the Postfix SMTP server
394 passes through to the SASL plug-in implementation that is se‐
395 lected with smtpd_sasl_type.
396 smtpd_sasl_type (cyrus)
398 The SASL plug-in type that the Postfix SMTP server should use
399 for authentication.
400 Available in Postfix version 2.5 and later:
402 cyrus_sasl_config_path (empty)
404 Search path for Cyrus SASL application configuration files, cur‐
405 rently used only to locate the $smtpd_sasl_path.conf file.
406 Available in Postfix version 2.11 and later:
408 smtpd_sasl_service (smtp)
410 The service name that is passed to the SASL plug-in that is se‐
411 lected with smtpd_sasl_type and smtpd_sasl_path.
412 Available in Postfix version 3.4 and later:
414 smtpd_sasl_response_limit (12288)
416 The maximum length of a SASL client's response to a server chal‐
417 lenge.
418 Available in Postfix 3.6 and later:
420 smtpd_sasl_mechanism_filter (!external, static:rest)
422 If non-empty, a filter for the SASL mechanism names that the
423 Postfix SMTP server will announce in the EHLO response.
424
426 Detailed information about STARTTLS configuration may be found in the
427 TLS_README document.
428 smtpd_tls_security_level (empty)
430 The SMTP TLS security level for the Postfix SMTP server; when a
431 non-empty value is specified, this overrides the obsolete param‐
432 eters smtpd_use_tls and smtpd_enforce_tls.
433 smtpd_sasl_tls_security_options ($smtpd_sasl_security_options)
435 The SASL authentication security options that the Postfix SMTP
436 server uses for TLS encrypted SMTP sessions.
437 smtpd_starttls_timeout (see 'postconf -d' output)
439 The time limit for Postfix SMTP server write and read operations
440 during TLS startup and shutdown handshake procedures.
441 smtpd_tls_CAfile (empty)
443 A file containing (PEM format) CA certificates of root CAs
444 trusted to sign either remote SMTP client certificates or inter‐
445 mediate CA certificates.
446 smtpd_tls_CApath (empty)
448 A directory containing (PEM format) CA certificates of root CAs
449 trusted to sign either remote SMTP client certificates or inter‐
450 mediate CA certificates.
451 smtpd_tls_always_issue_session_ids (yes)
453 Force the Postfix SMTP server to issue a TLS session id, even
454 when TLS session caching is turned off (smtpd_tls_ses‐
455 sion_cache_database is empty).
456 smtpd_tls_ask_ccert (no)
458 Ask a remote SMTP client for a client certificate.
459 smtpd_tls_auth_only (no)
461 When TLS encryption is optional in the Postfix SMTP server, do
462 not announce or accept SASL authentication over unencrypted con‐
463 nections.
464 smtpd_tls_ccert_verifydepth (9)
466 The verification depth for remote SMTP client certificates.
467 smtpd_tls_cert_file (empty)
469 File with the Postfix SMTP server RSA certificate in PEM format.
470 smtpd_tls_exclude_ciphers (empty)
472 List of ciphers or cipher types to exclude from the SMTP server
473 cipher list at all TLS security levels.
474 smtpd_tls_dcert_file (empty)
476 File with the Postfix SMTP server DSA certificate in PEM format.
477 smtpd_tls_dh1024_param_file (empty)
479 File with DH parameters that the Postfix SMTP server should use
480 with non-export EDH ciphers.
481 smtpd_tls_dh512_param_file (empty)
483 File with DH parameters that the Postfix SMTP server should use
484 with export-grade EDH ciphers.
485 smtpd_tls_dkey_file ($smtpd_tls_dcert_file)
487 File with the Postfix SMTP server DSA private key in PEM format.
488 smtpd_tls_key_file ($smtpd_tls_cert_file)
490 File with the Postfix SMTP server RSA private key in PEM format.
491 smtpd_tls_loglevel (0)
493 Enable additional Postfix SMTP server logging of TLS activity.
494 smtpd_tls_mandatory_ciphers (medium)
496 The minimum TLS cipher grade that the Postfix SMTP server will
497 use with mandatory TLS encryption.
498 smtpd_tls_mandatory_exclude_ciphers (empty)
500 Additional list of ciphers or cipher types to exclude from the
501 Postfix SMTP server cipher list at mandatory TLS security lev‐
502 els.
503 smtpd_tls_mandatory_protocols (see 'postconf -d' output)
505 TLS protocols accepted by the Postfix SMTP server with mandatory
506 TLS encryption.
507 smtpd_tls_received_header (no)
509 Request that the Postfix SMTP server produces Received: message
510 headers that include information about the protocol and cipher
511 used, as well as the remote SMTP client CommonName and client
512 certificate issuer CommonName.
513 smtpd_tls_req_ccert (no)
515 With mandatory TLS encryption, require a trusted remote SMTP
516 client certificate in order to allow TLS connections to proceed.
517 smtpd_tls_wrappermode (no)
519 Run the Postfix SMTP server in the non-standard "wrapper" mode,
520 instead of using the STARTTLS command.
521 tls_daemon_random_bytes (32)
523 The number of pseudo-random bytes that an smtp(8) or smtpd(8)
524 process requests from the tlsmgr(8) server in order to seed its
525 internal pseudo random number generator (PRNG).
526 tls_high_cipherlist (see 'postconf -d' output)
528 The OpenSSL cipherlist for "high" grade ciphers.
529 tls_medium_cipherlist (see 'postconf -d' output)
531 The OpenSSL cipherlist for "medium" or higher grade ciphers.
532 tls_low_cipherlist (see 'postconf -d' output)
534 The OpenSSL cipherlist for "low" or higher grade ciphers.
535 tls_export_cipherlist (see 'postconf -d' output)
537 The OpenSSL cipherlist for "export" or higher grade ciphers.
538 tls_null_cipherlist (eNULL:!aNULL)
540 The OpenSSL cipherlist for "NULL" grade ciphers that provide au‐
541 thentication without encryption.
542 Available in Postfix version 2.5 and later:
544 smtpd_tls_fingerprint_digest (see 'postconf -d' output)
546 The message digest algorithm to construct remote SMTP
547 client-certificate fingerprints or public key fingerprints
548 (Postfix 2.9 and later) for check_ccert_access and per‐
549 mit_tls_clientcerts.
550 Available in Postfix version 2.6 and later:
552 smtpd_tls_protocols (see postconf -d output)
554 TLS protocols accepted by the Postfix SMTP server with oppor‐
555 tunistic TLS encryption.
556 smtpd_tls_ciphers (medium)
558 The minimum TLS cipher grade that the Postfix SMTP server will
559 use with opportunistic TLS encryption.
560 smtpd_tls_eccert_file (empty)
562 File with the Postfix SMTP server ECDSA certificate in PEM for‐
563 mat.
564 smtpd_tls_eckey_file ($smtpd_tls_eccert_file)
566 File with the Postfix SMTP server ECDSA private key in PEM for‐
567 mat.
568 smtpd_tls_eecdh_grade (see 'postconf -d' output)
570 The Postfix SMTP server security grade for ephemeral ellip‐
571 tic-curve Diffie-Hellman (EECDH) key exchange.
572 tls_eecdh_strong_curve (prime256v1)
574 The elliptic curve used by the Postfix SMTP server for sensibly
575 strong ephemeral ECDH key exchange.
576 tls_eecdh_ultra_curve (secp384r1)
578 The elliptic curve used by the Postfix SMTP server for maximally
579 strong ephemeral ECDH key exchange.
580 Available in Postfix version 2.8 and later:
582 tls_preempt_cipherlist (no)
584 With SSLv3 and later, use the Postfix SMTP server's cipher pref‐
585 erence order instead of the remote client's cipher preference
586 order.
587 tls_disable_workarounds (see 'postconf -d' output)
589 List or bit-mask of OpenSSL bug work-arounds to disable.
590 Available in Postfix version 2.11 and later:
592 tlsmgr_service_name (tlsmgr)
594 The name of the tlsmgr(8) service entry in master.cf.
595 Available in Postfix version 3.0 and later:
597 tls_session_ticket_cipher (Postfix >= 3.0: aes-256-cbc, Postfix < 3.0:
599 aes-128-cbc)
600 Algorithm used to encrypt RFC5077 TLS session tickets.
601 Available in Postfix version 3.2 and later:
603 tls_eecdh_auto_curves (see 'postconf -d' output)
605 The prioritized list of elliptic curves supported by the Postfix
606 SMTP client and server.
607 Available in Postfix version 3.4 and later:
609 smtpd_tls_chain_files (empty)
611 List of one or more PEM files, each holding one or more private
612 keys directly followed by a corresponding certificate chain.
613 tls_server_sni_maps (empty)
615 Optional lookup tables that map names received from remote SMTP
616 clients via the TLS Server Name Indication (SNI) extension to
617 the appropriate keys and certificate chains.
618 Available in Postfix 3.5, 3.4.6, 3.3.5, 3.2.10, 3.1.13 and later:
620 tls_fast_shutdown_enable (yes)
622 A workaround for implementations that hang Postfix while shut‐
623 ting down a TLS session, until Postfix times out.
624 Available in Postfix 3.5 and later:
626 info_log_address_format (external)
628 The email address form that will be used in non-debug logging
629 (info, warning, etc.).
630
632 The following configuration parameters exist for compatibility with
633 Postfix versions before 2.3. Support for these will be removed in a fu‐
634 ture release.
635 smtpd_use_tls (no)
637 Opportunistic TLS: announce STARTTLS support to remote SMTP
638 clients, but do not require that clients use TLS encryption.
639 smtpd_enforce_tls (no)
641 Mandatory TLS: announce STARTTLS support to remote SMTP clients,
642 and require that clients use TLS encryption.
643 smtpd_tls_cipherlist (empty)
645 Obsolete Postfix < 2.3 control for the Postfix SMTP server TLS
646 cipher list.
647
649 Preliminary SMTPUTF8 support is introduced with Postfix 3.0.
650 smtputf8_enable (yes)
652 Enable preliminary SMTPUTF8 support for the protocols described
653 in RFC 6531..6533.
654 strict_smtputf8 (no)
656 Enable stricter enforcement of the SMTPUTF8 protocol.
657 smtputf8_autodetect_classes (sendmail, verify)
659 Detect that a message requires SMTPUTF8 support for the speci‐
660 fied mail origin classes.
661 Available in Postfix version 3.2 and later:
663 enable_idna2003_compatibility (no)
665 Enable 'transitional' compatibility between IDNA2003 and
666 IDNA2008, when converting UTF-8 domain names to/from the ASCII
667 form that is used for DNS lookups.
668
670 With VERP style delivery, each recipient of a message receives a cus‐
671 tomized copy of the message with his/her own recipient address encoded
672 in the envelope sender address. The VERP_README file describes config‐
673 uration and operation details of Postfix support for variable envelope
674 return path addresses. VERP style delivery is requested with the SMTP
675 XVERP command or with the "sendmail -V" command-line option and is
676 available in Postfix version 1.1 and later.
677 default_verp_delimiters (+=)
679 The two default VERP delimiter characters.
680 verp_delimiter_filter (-=+)
682 The characters Postfix accepts as VERP delimiter characters on
683 the Postfix sendmail(1) command line and in SMTP commands.
684 Available in Postfix version 1.1 and 2.0:
686 authorized_verp_clients ($mynetworks)
688 What remote SMTP clients are allowed to specify the XVERP com‐
689 mand.
690 Available in Postfix version 2.1 and later:
692 smtpd_authorized_verp_clients ($authorized_verp_clients)
694 What remote SMTP clients are allowed to specify the XVERP com‐
695 mand.
696
698 The DEBUG_README document describes how to debug parts of the Postfix
699 mail system. The methods vary from making the software log a lot of de‐
700 tail, to running some daemon processes under control of a call tracer
701 or debugger.
702 debug_peer_level (2)
704 The increment in verbose logging level when a nexthop destina‐
705 tion, remote client or server name or network address matches a
706 pattern given with the debug_peer_list parameter.
707 debug_peer_list (empty)
709 Optional list of nexthop destination, remote client or server
710 name or network address patterns that, if matched, cause the
711 verbose logging level to increase by the amount specified in
712 $debug_peer_level.
713 error_notice_recipient (postmaster)
715 The recipient of postmaster notifications about mail delivery
716 problems that are caused by policy, resource, software or proto‐
717 col errors.
718 internal_mail_filter_classes (empty)
720 What categories of Postfix-generated mail are subject to be‐
721 fore-queue content inspection by non_smtpd_milters,
722 header_checks and body_checks.
723 notify_classes (resource, software)
725 The list of error classes that are reported to the postmaster.
726 smtpd_reject_footer (empty)
728 Optional information that is appended after each Postfix SMTP
729 server 4XX or 5XX response.
730 soft_bounce (no)
732 Safety net to keep mail queued that would otherwise be returned
733 to the sender.
734 Available in Postfix version 2.1 and later:
736 smtpd_authorized_xclient_hosts (empty)
738 What remote SMTP clients are allowed to use the XCLIENT feature.
739 Available in Postfix version 2.10 and later:
741 smtpd_log_access_permit_actions (empty)
743 Enable logging of the named "permit" actions in SMTP server ac‐
744 cess lists (by default, the SMTP server logs "reject" actions
745 but not "permit" actions).
746
748 As of Postfix version 2.0, the SMTP server rejects mail for unknown re‐
749 cipients. This prevents the mail queue from clogging up with undeliver‐
750 able MAILER-DAEMON messages. Additional information on this topic is in
751 the LOCAL_RECIPIENT_README and ADDRESS_CLASS_README documents.
752 show_user_unknown_table_name (yes)
754 Display the name of the recipient table in the "User unknown"
755 responses.
756 canonical_maps (empty)
758 Optional address mapping lookup tables for message headers and
759 envelopes.
760 recipient_canonical_maps (empty)
762 Optional address mapping lookup tables for envelope and header
763 recipient addresses.
764 sender_canonical_maps (empty)
766 Optional address mapping lookup tables for envelope and header
767 sender addresses.
768 Parameters concerning known/unknown local recipients:
770 mydestination ($myhostname, localhost.$mydomain, localhost)
772 The list of domains that are delivered via the $local_transport
773 mail delivery transport.
774 inet_interfaces (all)
776 The network interface addresses that this mail system receives
777 mail on.
778 proxy_interfaces (empty)
780 The network interface addresses that this mail system receives
781 mail on by way of a proxy or network address translation unit.
782 inet_protocols (see 'postconf -d output')
784 The Internet protocols Postfix will attempt to use when making
785 or accepting connections.
786 local_recipient_maps (proxy:unix:passwd.byname $alias_maps)
788 Lookup tables with all names or addresses of local recipients: a
789 recipient address is local when its domain matches $mydestina‐
790 tion, $inet_interfaces or $proxy_interfaces.
791 unknown_local_recipient_reject_code (550)
793 The numerical Postfix SMTP server response code when a recipient
794 address is local, and $local_recipient_maps specifies a list of
795 lookup tables that does not match the recipient.
796 Parameters concerning known/unknown recipients of relay destinations:
798 relay_domains (Postfix >= 3.0: empty, Postfix < 3.0: $mydestination)
800 What destination domains (and subdomains thereof) this system
801 will relay mail to.
802 relay_recipient_maps (empty)
804 Optional lookup tables with all valid addresses in the domains
805 that match $relay_domains.
806 unknown_relay_recipient_reject_code (550)
808 The numerical Postfix SMTP server reply code when a recipient
809 address matches $relay_domains, and relay_recipient_maps speci‐
810 fies a list of lookup tables that does not match the recipient
811 address.
812 Parameters concerning known/unknown recipients in virtual alias do‐
814 mains:
815 virtual_alias_domains ($virtual_alias_maps)
817 Postfix is final destination for the specified list of virtual
818 alias domains, that is, domains for which all addresses are
819 aliased to addresses in other local or remote domains.
820 virtual_alias_maps ($virtual_maps)
822 Optional lookup tables that alias specific mail addresses or do‐
823 mains to other local or remote address.
824 unknown_virtual_alias_reject_code (550)
826 The Postfix SMTP server reply code when a recipient address
827 matches $virtual_alias_domains, and $virtual_alias_maps speci‐
828 fies a list of lookup tables that does not match the recipient
829 address.
830 Parameters concerning known/unknown recipients in virtual mailbox do‐
832 mains:
833 virtual_mailbox_domains ($virtual_mailbox_maps)
835 Postfix is final destination for the specified list of domains;
836 mail is delivered via the $virtual_transport mail delivery
837 transport.
838 virtual_mailbox_maps (empty)
840 Optional lookup tables with all valid addresses in the domains
841 that match $virtual_mailbox_domains.
842 unknown_virtual_mailbox_reject_code (550)
844 The Postfix SMTP server reply code when a recipient address
845 matches $virtual_mailbox_domains, and $virtual_mailbox_maps
846 specifies a list of lookup tables that does not match the recip‐
847 ient address.
848
850 The following parameters limit resource usage by the SMTP server and/or
851 control client request rates.
852 line_length_limit (2048)
854 Upon input, long lines are chopped up into pieces of at most
855 this length; upon delivery, long lines are reconstructed.
856 queue_minfree (0)
858 The minimal amount of free space in bytes in the queue file sys‐
859 tem that is needed to receive mail.
860 message_size_limit (10240000)
862 The maximal size in bytes of a message, including envelope in‐
863 formation.
864 smtpd_recipient_limit (1000)
866 The maximal number of recipients that the Postfix SMTP server
867 accepts per message delivery request.
868 smtpd_timeout (normal: 300s, overload: 10s)
870 When the Postfix SMTP server wants to send an SMTP server re‐
871 sponse, how long the Postfix SMTP server will wait for an under‐
872 lying network write operation to complete; and when the Postfix
873 SMTP server Postfix wants to receive an SMTP client request, how
874 long the Postfix SMTP server will wait for an underlying network
875 read operation to complete.
876 smtpd_history_flush_threshold (100)
878 The maximal number of lines in the Postfix SMTP server command
879 history before it is flushed upon receipt of EHLO, RSET, or end
880 of DATA.
881 Available in Postfix version 2.3 and later:
883 smtpd_peername_lookup (yes)
885 Attempt to look up the remote SMTP client hostname, and verify
886 that the name matches the client IP address.
887 The per SMTP client connection count and request rate limits are imple‐
889 mented in co-operation with the anvil(8) service, and are available in
890 Postfix version 2.2 and later.
891 smtpd_client_connection_count_limit (50)
893 How many simultaneous connections any client is allowed to make
894 to this service.
895 smtpd_client_connection_rate_limit (0)
897 The maximal number of connection attempts any client is allowed
898 to make to this service per time unit.
899 smtpd_client_message_rate_limit (0)
901 The maximal number of message delivery requests that any client
902 is allowed to make to this service per time unit, regardless of
903 whether or not Postfix actually accepts those messages.
904 smtpd_client_recipient_rate_limit (0)
906 The maximal number of recipient addresses that any client is al‐
907 lowed to send to this service per time unit, regardless of
908 whether or not Postfix actually accepts those recipients.
909 smtpd_client_event_limit_exceptions ($mynetworks)
911 Clients that are excluded from smtpd_client_*_count/rate_limit
912 restrictions.
913 Available in Postfix version 2.3 and later:
915 smtpd_client_new_tls_session_rate_limit (0)
917 The maximal number of new (i.e., uncached) TLS sessions that a
918 remote SMTP client is allowed to negotiate with this service per
919 time unit.
920 Available in Postfix version 2.9 - 3.6:
922 smtpd_per_record_deadline (normal: no, overload: yes)
924 Change the behavior of the smtpd_timeout and smtpd_start‐
925 tls_timeout time limits, from a time limit per read or write
926 system call, to a time limit to send or receive a complete
927 record (an SMTP command line, SMTP response line, SMTP message
928 content line, or TLS protocol message).
929 Available in Postfix version 3.1 and later:
931 smtpd_client_auth_rate_limit (0)
933 The maximal number of AUTH commands that any client is allowed
934 to send to this service per time unit, regardless of whether or
935 not Postfix actually accepts those commands.
936 Available in Postfix version 3.7 and later:
938 smtpd_per_request_deadline (normal: no, overload: yes)
940 Change the behavior of the smtpd_timeout and smtpd_start‐
941 tls_timeout time limits, from a time limit per plaintext or TLS
942 read or write call, to a combined time limit for receiving a
943 complete SMTP request and for sending a complete SMTP response.
944 smtpd_min_data_rate (500)
946 The minimum plaintext data transfer rate in bytes/second for
947 DATA and BDAT requests, when deadlines are enabled with
948 smtpd_per_request_deadline.
949 header_from_format (standard)
951 The format of the Postfix-generated From: header.
952
954 When a remote SMTP client makes errors, the Postfix SMTP server can in‐
955 sert delays before responding. This can help to slow down run-away
956 software. The behavior is controlled by an error counter that counts
957 the number of errors within an SMTP session that a client makes without
958 delivering mail.
959 smtpd_error_sleep_time (1s)
961 With Postfix version 2.1 and later: the SMTP server response de‐
962 lay after a client has made more than $smtpd_soft_error_limit
963 errors, and fewer than $smtpd_hard_error_limit errors, without
964 delivering mail.
965 smtpd_soft_error_limit (10)
967 The number of errors a remote SMTP client is allowed to make
968 without delivering mail before the Postfix SMTP server slows
969 down all its responses.
970 smtpd_hard_error_limit (normal: 20, overload: 1)
972 The maximal number of errors a remote SMTP client is allowed to
973 make without delivering mail.
974 smtpd_junk_command_limit (normal: 100, overload: 1)
976 The number of junk commands (NOOP, VRFY, ETRN or RSET) that a
977 remote SMTP client can send before the Postfix SMTP server
978 starts to increment the error counter with each junk command.
979 Available in Postfix version 2.1 and later:
981 smtpd_recipient_overshoot_limit (1000)
983 The number of recipients that a remote SMTP client can send in
984 excess of the limit specified with $smtpd_recipient_limit, be‐
985 fore the Postfix SMTP server increments the per-session error
986 count for each excess recipient.
987
989 As of version 2.1, Postfix can be configured to delegate access policy
990 decisions to an external server that runs outside Postfix. See the
991 file SMTPD_POLICY_README for more information.
992 smtpd_policy_service_max_idle (300s)
994 The time after which an idle SMTPD policy service connection is
995 closed.
996 smtpd_policy_service_max_ttl (1000s)
998 The time after which an active SMTPD policy service connection
999 is closed.
1000 smtpd_policy_service_timeout (100s)
1002 The time limit for connecting to, writing to, or receiving from
1003 a delegated SMTPD policy server.
1004 Available in Postfix version 3.0 and later:
1006 smtpd_policy_service_default_action (451 4.3.5 Server configuration
1008 problem)
1009 The default action when an SMTPD policy service request fails.
1010 smtpd_policy_service_request_limit (0)
1012 The maximal number of requests per SMTPD policy service connec‐
1013 tion, or zero (no limit).
1014 smtpd_policy_service_try_limit (2)
1016 The maximal number of attempts to send an SMTPD policy service
1017 request before giving up.
1018 smtpd_policy_service_retry_delay (1s)
1020 The delay between attempts to resend a failed SMTPD policy ser‐
1021 vice request.
1022 Available in Postfix version 3.1 and later:
1024 smtpd_policy_service_policy_context (empty)
1026 Optional information that the Postfix SMTP server specifies in
1027 the "policy_context" attribute of a policy service request
1028 (originally, to share the same service endpoint among multiple
1029 check_policy_service clients).
1030
1032 The SMTPD_ACCESS_README document gives an introduction to all the SMTP
1033 server access control features.
1034 smtpd_delay_reject (yes)
1036 Wait until the RCPT TO command before evaluating
1037 $smtpd_client_restrictions, $smtpd_helo_restrictions and
1038 $smtpd_sender_restrictions, or wait until the ETRN command be‐
1039 fore evaluating $smtpd_client_restrictions and $smtpd_helo_re‐
1040 strictions.
1041 parent_domain_matches_subdomains (see 'postconf -d' output)
1043 A list of Postfix features where the pattern "example.com" also
1044 matches subdomains of example.com, instead of requiring an ex‐
1045 plicit ".example.com" pattern.
1046 smtpd_client_restrictions (empty)
1048 Optional restrictions that the Postfix SMTP server applies in
1049 the context of a client connection request.
1050 smtpd_helo_required (no)
1052 Require that a remote SMTP client introduces itself with the
1053 HELO or EHLO command before sending the MAIL command or other
1054 commands that require EHLO negotiation.
1055 smtpd_helo_restrictions (empty)
1057 Optional restrictions that the Postfix SMTP server applies in
1058 the context of a client HELO command.
1059 smtpd_sender_restrictions (empty)
1061 Optional restrictions that the Postfix SMTP server applies in
1062 the context of a client MAIL FROM command.
1063 smtpd_recipient_restrictions (see 'postconf -d' output)
1065 Optional restrictions that the Postfix SMTP server applies in
1066 the context of a client RCPT TO command, after smtpd_relay_re‐
1067 strictions.
1068 smtpd_etrn_restrictions (empty)
1070 Optional restrictions that the Postfix SMTP server applies in
1071 the context of a client ETRN command.
1072 allow_untrusted_routing (no)
1074 Forward mail with sender-specified routing (user[@%!]re‐
1075 mote[@%!]site) from untrusted clients to destinations matching
1076 $relay_domains.
1077 smtpd_restriction_classes (empty)
1079 User-defined aliases for groups of access restrictions.
1080 smtpd_null_access_lookup_key (<>)
1082 The lookup key to be used in SMTP access(5) tables instead of
1083 the null sender address.
1084 permit_mx_backup_networks (empty)
1086 Restrict the use of the permit_mx_backup SMTP access feature to
1087 only domains whose primary MX hosts match the listed networks.
1088 Available in Postfix version 2.0 and later:
1090 smtpd_data_restrictions (empty)
1092 Optional access restrictions that the Postfix SMTP server ap‐
1093 plies in the context of the SMTP DATA command.
1094 smtpd_expansion_filter (see 'postconf -d' output)
1096 What characters are allowed in $name expansions of RBL reply
1097 templates.
1098 Available in Postfix version 2.1 and later:
1100 smtpd_reject_unlisted_sender (no)
1102 Request that the Postfix SMTP server rejects mail from unknown
1103 sender addresses, even when no explicit reject_unlisted_sender
1104 access restriction is specified.
1105 smtpd_reject_unlisted_recipient (yes)
1107 Request that the Postfix SMTP server rejects mail for unknown
1108 recipient addresses, even when no explicit reject_unlisted_re‐
1109 cipient access restriction is specified.
1110 Available in Postfix version 2.2 and later:
1112 smtpd_end_of_data_restrictions (empty)
1114 Optional access restrictions that the Postfix SMTP server ap‐
1115 plies in the context of the SMTP END-OF-DATA command.
1116 Available in Postfix version 2.10 and later:
1118 smtpd_relay_restrictions (permit_mynetworks, permit_sasl_authenticated,
1120 defer_unauth_destination)
1121 Access restrictions for mail relay control that the Postfix SMTP
1122 server applies in the context of the RCPT TO command, before
1123 smtpd_recipient_restrictions.
1124
1126 Postfix version 2.1 introduces sender and recipient address verifica‐
1127 tion. This feature is implemented by sending probe email messages that
1128 are not actually delivered. This feature is requested via the re‐
1129 ject_unverified_sender and reject_unverified_recipient access restric‐
1130 tions. The status of verification probes is maintained by the ver‐
1131 ify(8) server. See the file ADDRESS_VERIFICATION_README for informa‐
1132 tion about how to configure and operate the Postfix sender/recipient
1133 address verification service.
1134 address_verify_poll_count (normal: 3, overload: 1)
1136 How many times to query the verify(8) service for the completion
1137 of an address verification request in progress.
1138 address_verify_poll_delay (3s)
1140 The delay between queries for the completion of an address veri‐
1141 fication request in progress.
1142 address_verify_sender ($double_bounce_sender)
1144 The sender address to use in address verification probes; prior
1145 to Postfix 2.5 the default was "postmaster".
1146 unverified_sender_reject_code (450)
1148 The numerical Postfix SMTP server response code when a recipient
1149 address is rejected by the reject_unverified_sender restriction.
1150 unverified_recipient_reject_code (450)
1152 The numerical Postfix SMTP server response when a recipient ad‐
1153 dress is rejected by the reject_unverified_recipient restric‐
1154 tion.
1155 Available in Postfix version 2.6 and later:
1157 unverified_sender_defer_code (450)
1159 The numerical Postfix SMTP server response code when a sender
1160 address probe fails due to a temporary error condition.
1161 unverified_recipient_defer_code (450)
1163 The numerical Postfix SMTP server response when a recipient ad‐
1164 dress probe fails due to a temporary error condition.
1165 unverified_sender_reject_reason (empty)
1167 The Postfix SMTP server's reply when rejecting mail with re‐
1168 ject_unverified_sender.
1169 unverified_recipient_reject_reason (empty)
1171 The Postfix SMTP server's reply when rejecting mail with re‐
1172 ject_unverified_recipient.
1173 unverified_sender_tempfail_action ($reject_tempfail_action)
1175 The Postfix SMTP server's action when reject_unverified_sender
1176 fails due to a temporary error condition.
1177 unverified_recipient_tempfail_action ($reject_tempfail_action)
1179 The Postfix SMTP server's action when reject_unverified_recipi‐
1180 ent fails due to a temporary error condition.
1181 Available with Postfix 2.9 and later:
1183 address_verify_sender_ttl (0s)
1185 The time between changes in the time-dependent portion of ad‐
1186 dress verification probe sender addresses.
1187
1189 The following parameters control numerical SMTP reply codes and/or text
1190 responses.
1191 access_map_reject_code (554)
1193 The numerical Postfix SMTP server response code for an access(5)
1194 map "reject" action.
1195 defer_code (450)
1197 The numerical Postfix SMTP server response code when a remote
1198 SMTP client request is rejected by the "defer" restriction.
1199 invalid_hostname_reject_code (501)
1201 The numerical Postfix SMTP server response code when the client
1202 HELO or EHLO command parameter is rejected by the reject_in‐
1203 valid_helo_hostname restriction.
1204 maps_rbl_reject_code (554)
1206 The numerical Postfix SMTP server response code when a remote
1207 SMTP client request is blocked by the reject_rbl_client, re‐
1208 ject_rhsbl_client, reject_rhsbl_reverse_client, re‐
1209 ject_rhsbl_sender or reject_rhsbl_recipient restriction.
1210 non_fqdn_reject_code (504)
1212 The numerical Postfix SMTP server reply code when a client re‐
1213 quest is rejected by the reject_non_fqdn_helo_hostname, re‐
1214 ject_non_fqdn_sender or reject_non_fqdn_recipient restriction.
1215 plaintext_reject_code (450)
1217 The numerical Postfix SMTP server response code when a request
1218 is rejected by the reject_plaintext_session restriction.
1219 reject_code (554)
1221 The numerical Postfix SMTP server response code when a remote
1222 SMTP client request is rejected by the "reject" restriction.
1223 relay_domains_reject_code (554)
1225 The numerical Postfix SMTP server response code when a client
1226 request is rejected by the reject_unauth_destination recipient
1227 restriction.
1228 unknown_address_reject_code (450)
1230 The numerical response code when the Postfix SMTP server rejects
1231 a sender or recipient address because its domain is unknown.
1232 unknown_client_reject_code (450)
1234 The numerical Postfix SMTP server response code when a client
1235 without valid address <=> name mapping is rejected by the re‐
1236 ject_unknown_client_hostname restriction.
1237 unknown_hostname_reject_code (450)
1239 The numerical Postfix SMTP server response code when the host‐
1240 name specified with the HELO or EHLO command is rejected by the
1241 reject_unknown_helo_hostname restriction.
1242 Available in Postfix version 2.0 and later:
1244 default_rbl_reply (see 'postconf -d' output)
1246 The default Postfix SMTP server response template for a request
1247 that is rejected by an RBL-based restriction.
1248 multi_recipient_bounce_reject_code (550)
1250 The numerical Postfix SMTP server response code when a remote
1251 SMTP client request is blocked by the reject_multi_recipi‐
1252 ent_bounce restriction.
1253 rbl_reply_maps (empty)
1255 Optional lookup tables with RBL response templates.
1256 Available in Postfix version 2.6 and later:
1258 access_map_defer_code (450)
1260 The numerical Postfix SMTP server response code for an access(5)
1261 map "defer" action, including "defer_if_permit" or "defer_if_re‐
1262 ject".
1263 reject_tempfail_action (defer_if_permit)
1265 The Postfix SMTP server's action when a reject-type restriction
1266 fails due to a temporary error condition.
1267 unknown_helo_hostname_tempfail_action ($reject_tempfail_action)
1269 The Postfix SMTP server's action when reject_unknown_helo_host‐
1270 name fails due to a temporary error condition.
1271 unknown_address_tempfail_action ($reject_tempfail_action)
1273 The Postfix SMTP server's action when reject_unknown_sender_do‐
1274 main or reject_unknown_recipient_domain fail due to a temporary
1275 error condition.
1276
1278 config_directory (see 'postconf -d' output)
1279 The default location of the Postfix main.cf and master.cf con‐
1280 figuration files.
1281 daemon_timeout (18000s)
1283 How much time a Postfix daemon process may take to handle a re‐
1284 quest before it is terminated by a built-in watchdog timer.
1285 command_directory (see 'postconf -d' output)
1287 The location of all postfix administrative commands.
1288 double_bounce_sender (double-bounce)
1290 The sender address of postmaster notifications that are gener‐
1291 ated by the mail system.
1292 ipc_timeout (3600s)
1294 The time limit for sending or receiving information over an in‐
1295 ternal communication channel.
1296 mail_name (Postfix)
1298 The mail system name that is displayed in Received: headers, in
1299 the SMTP greeting banner, and in bounced mail.
1300 mail_owner (postfix)
1302 The UNIX system account that owns the Postfix queue and most
1303 Postfix daemon processes.
1304 max_idle (100s)
1306 The maximum amount of time that an idle Postfix daemon process
1307 waits for an incoming connection before terminating voluntarily.
1308 max_use (100)
1310 The maximal number of incoming connections that a Postfix daemon
1311 process will service before terminating voluntarily.
1312 myhostname (see 'postconf -d' output)
1314 The internet hostname of this mail system.
1315 mynetworks (see 'postconf -d' output)
1317 The list of "trusted" remote SMTP clients that have more privi‐
1318 leges than "strangers".
1319 myorigin ($myhostname)
1321 The domain name that locally-posted mail appears to come from,
1322 and that locally posted mail is delivered to.
1323 process_id (read-only)
1325 The process ID of a Postfix command or daemon process.
1326 process_name (read-only)
1328 The process name of a Postfix command or daemon process.
1329 queue_directory (see 'postconf -d' output)
1331 The location of the Postfix top-level queue directory.
1332 recipient_delimiter (empty)
1334 The set of characters that can separate an email address local‐
1335 part, user name, or a .forward file name from its extension.
1336 smtpd_banner ($myhostname ESMTP $mail_name)
1338 The text that follows the 220 status code in the SMTP greeting
1339 banner.
1340 syslog_facility (mail)
1342 The syslog facility of Postfix logging.
1343 syslog_name (see 'postconf -d' output)
1345 A prefix that is prepended to the process name in syslog
1346 records, so that, for example, "smtpd" becomes "prefix/smtpd".
1347 Available in Postfix version 2.2 and later:
1349 smtpd_forbidden_commands (CONNECT GET POST regexp:{{/^[^A-Z]/ Bogus}})
1351 List of commands that cause the Postfix SMTP server to immedi‐
1352 ately terminate the session with a 221 code.
1353 Available in Postfix version 2.5 and later:
1355 smtpd_client_port_logging (no)
1357 Enable logging of the remote SMTP client port in addition to the
1358 hostname and IP address.
1359 Available in Postfix 3.3 and later:
1361 service_name (read-only)
1363 The master.cf service name of a Postfix daemon process.
1364 Available in Postfix 3.4 and later:
1366 smtpd_reject_footer_maps (empty)
1368 Lookup tables, indexed by the complete Postfix SMTP server 4xx
1369 or 5xx response, with reject footer templates.
1370
1372 anvil(8), connection/rate limiting
1373 cleanup(8), message canonicalization
1374 tlsmgr(8), TLS session and PRNG management
1375 trivial-rewrite(8), address resolver
1376 verify(8), address verification service
1377 postconf(5), configuration parameters
1378 master(5), generic daemon options
1379 master(8), process manager
1380 postlogd(8), Postfix logging
1381 syslogd(8), system logging
1382
1384 Use "postconf readme_directory" or "postconf html_directory" to locate
1385 this information.
1386 ADDRESS_CLASS_README, blocking unknown hosted or relay recipients
1387 ADDRESS_REWRITING_README, Postfix address manipulation
1388 BDAT_README, Postfix CHUNKING support
1389 FILTER_README, external after-queue content filter
1390 LOCAL_RECIPIENT_README, blocking unknown local recipients
1391 MILTER_README, before-queue mail filter applications
1392 SMTPD_ACCESS_README, built-in access policies
1393 SMTPD_POLICY_README, external policy server
1394 SMTPD_PROXY_README, external before-queue content filter
1395 SASL_README, Postfix SASL howto
1396 TLS_README, Postfix STARTTLS howto
1397 VERP_README, Postfix XVERP extension
1398 XCLIENT_README, Postfix XCLIENT extension
1399 XFORWARD_README, Postfix XFORWARD extension
1400
1402 The Secure Mailer license must be distributed with this software.
1403
1405 Wietse Venema
1406 IBM T.J. Watson Research
1407 P.O. Box 704
1408 Yorktown Heights, NY 10598, USA
1409 Wietse Venema
1411 Google, Inc.
1412 111 8th Avenue
1413 New York, NY 10011, USA
1414 SASL support originally by:
1416 Till Franke
1417 SuSE Rhein/Main AG
1418 65760 Eschborn, Germany
1419 TLS support originally by:
1421 Lutz Jaenicke
1422 BTU Cottbus
1423 Allgemeine Elektrotechnik
1424 Universitaetsplatz 3-4
1425 D-03044 Cottbus, Germany
1426 Revised TLS support by:
1428 Victor Duchovni
1429 Morgan Stanley
1430 SMTPD(8)