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 and later:
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
170 See the ADDRESS_REWRITING_README document for a detailed discussion of
171 Postfix address rewriting.
172 receive_override_options (empty)
174 Enable or disable recipient validation, built-in content filter‐
175 ing, or address mapping.
176 Available in Postfix version 2.2 and later:
178 local_header_rewrite_clients (permit_inet_interfaces)
180 Rewrite message header addresses in mail from these clients and
181 update incomplete addresses with the domain name in $myorigin or
182 $mydomain; either don't rewrite message headers from other
183 clients at all, or rewrite message headers and update incomplete
184 addresses with the domain specified in the remote_header_re‐
185 write_domain parameter.
186
188 Available in Postfix version 2.10 and later:
189 smtpd_upstream_proxy_protocol (empty)
191 The name of the proxy protocol used by an optional before-smtpd
192 proxy agent.
193 smtpd_upstream_proxy_timeout (5s)
195 The time limit for the proxy protocol specified with the
196 smtpd_upstream_proxy_protocol parameter.
197
199 As of version 1.0, Postfix can be configured to send new mail to an ex‐
200 ternal content filter AFTER the mail is queued. This content filter is
201 expected to inject mail back into a (Postfix or other) MTA for further
202 delivery. See the FILTER_README document for details.
203 content_filter (empty)
205 After the message is queued, send the entire message to the
206 specified transport:destination.
207
209 As of version 2.1, the Postfix SMTP server can be configured to send
210 incoming mail to a real-time SMTP-based content filter BEFORE mail is
211 queued. This content filter is expected to inject mail back into Post‐
212 fix. See the SMTPD_PROXY_README document for details on how to config‐
213 ure and operate this feature.
214 smtpd_proxy_filter (empty)
216 The hostname and TCP port of the mail filtering proxy server.
217 smtpd_proxy_ehlo ($myhostname)
219 How the Postfix SMTP server announces itself to the proxy fil‐
220 ter.
221 smtpd_proxy_options (empty)
223 List of options that control how the Postfix SMTP server commu‐
224 nicates with a before-queue content filter.
225 smtpd_proxy_timeout (100s)
227 The time limit for connecting to a proxy filter and for sending
228 or receiving information.
229
231 As of version 2.3, Postfix supports the Sendmail version 8 Milter (mail
232 filter) protocol. These content filters run outside Postfix. They can
233 inspect the SMTP command stream and the message content, and can re‐
234 quest modifications before mail is queued. For details see the MIL‐
235 TER_README document.
236 smtpd_milters (empty)
238 A list of Milter (mail filter) applications for new mail that
239 arrives via the Postfix smtpd(8) server.
240 milter_protocol (6)
242 The mail filter protocol version and optional protocol exten‐
243 sions for communication with a Milter application; prior to
244 Postfix 2.6 the default protocol is 2.
245 milter_default_action (tempfail)
247 The default action when a Milter (mail filter) response is un‐
248 available (for example, bad Postfix configuration or Milter
249 failure).
250 milter_macro_daemon_name ($myhostname)
252 The {daemon_name} macro value for Milter (mail filter) applica‐
253 tions.
254 milter_macro_v ($mail_name $mail_version)
256 The {v} macro value for Milter (mail filter) applications.
257 milter_connect_timeout (30s)
259 The time limit for connecting to a Milter (mail filter) applica‐
260 tion, and for negotiating protocol options.
261 milter_command_timeout (30s)
263 The time limit for sending an SMTP command to a Milter (mail
264 filter) application, and for receiving the response.
265 milter_content_timeout (300s)
267 The time limit for sending message content to a Milter (mail
268 filter) application, and for receiving the response.
269 milter_connect_macros (see 'postconf -d' output)
271 The macros that are sent to Milter (mail filter) applications
272 after completion of an SMTP connection.
273 milter_helo_macros (see 'postconf -d' output)
275 The macros that are sent to Milter (mail filter) applications
276 after the SMTP HELO or EHLO command.
277 milter_mail_macros (see 'postconf -d' output)
279 The macros that are sent to Milter (mail filter) applications
280 after the SMTP MAIL FROM command.
281 milter_rcpt_macros (see 'postconf -d' output)
283 The macros that are sent to Milter (mail filter) applications
284 after the SMTP RCPT TO command.
285 milter_data_macros (see 'postconf -d' output)
287 The macros that are sent to version 4 or higher Milter (mail
288 filter) applications after the SMTP DATA command.
289 milter_unknown_command_macros (see 'postconf -d' output)
291 The macros that are sent to version 3 or higher Milter (mail
292 filter) applications after an unknown SMTP command.
293 milter_end_of_header_macros (see 'postconf -d' output)
295 The macros that are sent to Milter (mail filter) applications
296 after the end of the message header.
297 milter_end_of_data_macros (see 'postconf -d' output)
299 The macros that are sent to Milter (mail filter) applications
300 after the message end-of-data.
301 Available in Postfix version 3.1 and later:
303 milter_macro_defaults (empty)
305 Optional list of name=value pairs that specify default values
306 for arbitrary macros that Postfix may send to Milter applica‐
307 tions.
308 Available in Postfix version 3.2 and later:
310 smtpd_milter_maps (empty)
312 Lookup tables with Milter settings per remote SMTP client IP ad‐
313 dress.
314
316 The following parameters are applicable for both built-in and external
317 content filters.
318 Available in Postfix version 2.1 and later:
320 receive_override_options (empty)
322 Enable or disable recipient validation, built-in content filter‐
323 ing, or address mapping.
324
326 The following parameters are applicable for both before-queue and af‐
327 ter-queue content filtering.
328 Available in Postfix version 2.1 and later:
330 smtpd_authorized_xforward_hosts (empty)
332 What remote SMTP clients are allowed to use the XFORWARD fea‐
333 ture.
334
336 Postfix SASL support (RFC 4954) can be used to authenticate remote SMTP
337 clients to the Postfix SMTP server, and to authenticate the Postfix
338 SMTP client to a remote SMTP server. See the SASL_README document for
339 details.
340 broken_sasl_auth_clients (no)
342 Enable interoperability with remote SMTP clients that implement
343 an obsolete version of the AUTH command (RFC 4954).
344 smtpd_sasl_auth_enable (no)
346 Enable SASL authentication in the Postfix SMTP server.
347 smtpd_sasl_local_domain (empty)
349 The name of the Postfix SMTP server's local SASL authentication
350 realm.
351 smtpd_sasl_security_options (noanonymous)
353 Postfix SMTP server SASL security options; as of Postfix 2.3 the
354 list of available features depends on the SASL server implemen‐
355 tation that is selected with smtpd_sasl_type.
356 smtpd_sender_login_maps (empty)
358 Optional lookup table with the SASL login names that own the
359 sender (MAIL FROM) addresses.
360 Available in Postfix version 2.1 and later:
362 smtpd_sasl_exceptions_networks (empty)
364 What remote SMTP clients the Postfix SMTP server will not offer
365 AUTH support to.
366 Available in Postfix version 2.1 and 2.2:
368 smtpd_sasl_application_name (smtpd)
370 The application name that the Postfix SMTP server uses for SASL
371 server initialization.
372 Available in Postfix version 2.3 and later:
374 smtpd_sasl_authenticated_header (no)
376 Report the SASL authenticated user name in the smtpd(8) Received
377 message header.
378 smtpd_sasl_path (smtpd)
380 Implementation-specific information that the Postfix SMTP server
381 passes through to the SASL plug-in implementation that is se‐
382 lected with smtpd_sasl_type.
383 smtpd_sasl_type (cyrus)
385 The SASL plug-in type that the Postfix SMTP server should use
386 for authentication.
387 Available in Postfix version 2.5 and later:
389 cyrus_sasl_config_path (empty)
391 Search path for Cyrus SASL application configuration files, cur‐
392 rently used only to locate the $smtpd_sasl_path.conf file.
393 Available in Postfix version 2.11 and later:
395 smtpd_sasl_service (smtp)
397 The service name that is passed to the SASL plug-in that is se‐
398 lected with smtpd_sasl_type and smtpd_sasl_path.
399 Available in Postfix version 3.4 and later:
401 smtpd_sasl_response_limit (12288)
403 The maximum length of a SASL client's response to a server chal‐
404 lenge.
405 Available in Postfix 3.6 and later:
407 smtpd_sasl_mechanism_filter (!external, static:rest)
409 If non-empty, a filter for the SASL mechanism names that the
410 Postfix SMTP server will announce in the EHLO response.
411
413 Detailed information about STARTTLS configuration may be found in the
414 TLS_README document.
415 smtpd_tls_security_level (empty)
417 The SMTP TLS security level for the Postfix SMTP server; when a
418 non-empty value is specified, this overrides the obsolete param‐
419 eters smtpd_use_tls and smtpd_enforce_tls.
420 smtpd_sasl_tls_security_options ($smtpd_sasl_security_options)
422 The SASL authentication security options that the Postfix SMTP
423 server uses for TLS encrypted SMTP sessions.
424 smtpd_starttls_timeout (see 'postconf -d' output)
426 The time limit for Postfix SMTP server write and read operations
427 during TLS startup and shutdown handshake procedures.
428 smtpd_tls_CAfile (empty)
430 A file containing (PEM format) CA certificates of root CAs
431 trusted to sign either remote SMTP client certificates or inter‐
432 mediate CA certificates.
433 smtpd_tls_CApath (empty)
435 A directory containing (PEM format) CA certificates of root CAs
436 trusted to sign either remote SMTP client certificates or inter‐
437 mediate CA certificates.
438 smtpd_tls_always_issue_session_ids (yes)
440 Force the Postfix SMTP server to issue a TLS session id, even
441 when TLS session caching is turned off (smtpd_tls_ses‐
442 sion_cache_database is empty).
443 smtpd_tls_ask_ccert (no)
445 Ask a remote SMTP client for a client certificate.
446 smtpd_tls_auth_only (no)
448 When TLS encryption is optional in the Postfix SMTP server, do
449 not announce or accept SASL authentication over unencrypted con‐
450 nections.
451 smtpd_tls_ccert_verifydepth (9)
453 The verification depth for remote SMTP client certificates.
454 smtpd_tls_cert_file (empty)
456 File with the Postfix SMTP server RSA certificate in PEM format.
457 smtpd_tls_exclude_ciphers (empty)
459 List of ciphers or cipher types to exclude from the SMTP server
460 cipher list at all TLS security levels.
461 smtpd_tls_dcert_file (empty)
463 File with the Postfix SMTP server DSA certificate in PEM format.
464 smtpd_tls_dh1024_param_file (empty)
466 File with DH parameters that the Postfix SMTP server should use
467 with non-export EDH ciphers.
468 smtpd_tls_dh512_param_file (empty)
470 File with DH parameters that the Postfix SMTP server should use
471 with export-grade EDH ciphers.
472 smtpd_tls_dkey_file ($smtpd_tls_dcert_file)
474 File with the Postfix SMTP server DSA private key in PEM format.
475 smtpd_tls_key_file ($smtpd_tls_cert_file)
477 File with the Postfix SMTP server RSA private key in PEM format.
478 smtpd_tls_loglevel (0)
480 Enable additional Postfix SMTP server logging of TLS activity.
481 smtpd_tls_mandatory_ciphers (medium)
483 The minimum TLS cipher grade that the Postfix SMTP server will
484 use with mandatory TLS encryption.
485 smtpd_tls_mandatory_exclude_ciphers (empty)
487 Additional list of ciphers or cipher types to exclude from the
488 Postfix SMTP server cipher list at mandatory TLS security lev‐
489 els.
490 smtpd_tls_mandatory_protocols (see 'postconf -d' output)
492 TLS protocols accepted by the Postfix SMTP server with mandatory
493 TLS encryption.
494 smtpd_tls_received_header (no)
496 Request that the Postfix SMTP server produces Received: message
497 headers that include information about the protocol and cipher
498 used, as well as the remote SMTP client CommonName and client
499 certificate issuer CommonName.
500 smtpd_tls_req_ccert (no)
502 With mandatory TLS encryption, require a trusted remote SMTP
503 client certificate in order to allow TLS connections to proceed.
504 smtpd_tls_wrappermode (no)
506 Run the Postfix SMTP server in the non-standard "wrapper" mode,
507 instead of using the STARTTLS command.
508 tls_daemon_random_bytes (32)
510 The number of pseudo-random bytes that an smtp(8) or smtpd(8)
511 process requests from the tlsmgr(8) server in order to seed its
512 internal pseudo random number generator (PRNG).
513 tls_high_cipherlist (see 'postconf -d' output)
515 The OpenSSL cipherlist for "high" grade ciphers.
516 tls_medium_cipherlist (see 'postconf -d' output)
518 The OpenSSL cipherlist for "medium" or higher grade ciphers.
519 tls_low_cipherlist (see 'postconf -d' output)
521 The OpenSSL cipherlist for "low" or higher grade ciphers.
522 tls_export_cipherlist (see 'postconf -d' output)
524 The OpenSSL cipherlist for "export" or higher grade ciphers.
525 tls_null_cipherlist (eNULL:!aNULL)
527 The OpenSSL cipherlist for "NULL" grade ciphers that provide au‐
528 thentication without encryption.
529 Available in Postfix version 2.5 and later:
531 smtpd_tls_fingerprint_digest (see 'postconf -d' output)
533 The message digest algorithm to construct remote SMTP
534 client-certificate fingerprints or public key fingerprints
535 (Postfix 2.9 and later) for check_ccert_access and per‐
536 mit_tls_clientcerts.
537 Available in Postfix version 2.6 and later:
539 smtpd_tls_protocols (see postconf -d output)
541 TLS protocols accepted by the Postfix SMTP server with oppor‐
542 tunistic TLS encryption.
543 smtpd_tls_ciphers (medium)
545 The minimum TLS cipher grade that the Postfix SMTP server will
546 use with opportunistic TLS encryption.
547 smtpd_tls_eccert_file (empty)
549 File with the Postfix SMTP server ECDSA certificate in PEM for‐
550 mat.
551 smtpd_tls_eckey_file ($smtpd_tls_eccert_file)
553 File with the Postfix SMTP server ECDSA private key in PEM for‐
554 mat.
555 smtpd_tls_eecdh_grade (see 'postconf -d' output)
557 The Postfix SMTP server security grade for ephemeral ellip‐
558 tic-curve Diffie-Hellman (EECDH) key exchange.
559 tls_eecdh_strong_curve (prime256v1)
561 The elliptic curve used by the Postfix SMTP server for sensibly
562 strong ephemeral ECDH key exchange.
563 tls_eecdh_ultra_curve (secp384r1)
565 The elliptic curve used by the Postfix SMTP server for maximally
566 strong ephemeral ECDH key exchange.
567 Available in Postfix version 2.8 and later:
569 tls_preempt_cipherlist (no)
571 With SSLv3 and later, use the Postfix SMTP server's cipher pref‐
572 erence order instead of the remote client's cipher preference
573 order.
574 tls_disable_workarounds (see 'postconf -d' output)
576 List or bit-mask of OpenSSL bug work-arounds to disable.
577 Available in Postfix version 2.11 and later:
579 tlsmgr_service_name (tlsmgr)
581 The name of the tlsmgr(8) service entry in master.cf.
582 Available in Postfix version 3.0 and later:
584 tls_session_ticket_cipher (Postfix >= 3.0: aes-256-cbc, Postfix < 3.0:
586 aes-128-cbc)
587 Algorithm used to encrypt RFC5077 TLS session tickets.
588 Available in Postfix version 3.2 and later:
590 tls_eecdh_auto_curves (see 'postconf -d' output)
592 The prioritized list of elliptic curves supported by the Postfix
593 SMTP client and server.
594 Available in Postfix version 3.4 and later:
596 smtpd_tls_chain_files (empty)
598 List of one or more PEM files, each holding one or more private
599 keys directly followed by a corresponding certificate chain.
600 tls_server_sni_maps (empty)
602 Optional lookup tables that map names received from remote SMTP
603 clients via the TLS Server Name Indication (SNI) extension to
604 the appropriate keys and certificate chains.
605 Available in Postfix 3.5, 3.4.6, 3.3.5, 3.2.10, 3.1.13 and later:
607 tls_fast_shutdown_enable (yes)
609 A workaround for implementations that hang Postfix while shut‐
610 ting down a TLS session, until Postfix times out.
611 Available in Postfix 3.5 and later:
613 info_log_address_format (external)
615 The email address form that will be used in non-debug logging
616 (info, warning, etc.).
617
619 The following configuration parameters exist for compatibility with
620 Postfix versions before 2.3. Support for these will be removed in a fu‐
621 ture release.
622 smtpd_use_tls (no)
624 Opportunistic TLS: announce STARTTLS support to remote SMTP
625 clients, but do not require that clients use TLS encryption.
626 smtpd_enforce_tls (no)
628 Mandatory TLS: announce STARTTLS support to remote SMTP clients,
629 and require that clients use TLS encryption.
630 smtpd_tls_cipherlist (empty)
632 Obsolete Postfix < 2.3 control for the Postfix SMTP server TLS
633 cipher list.
634
636 Preliminary SMTPUTF8 support is introduced with Postfix 3.0.
637 smtputf8_enable (yes)
639 Enable preliminary SMTPUTF8 support for the protocols described
640 in RFC 6531..6533.
641 strict_smtputf8 (no)
643 Enable stricter enforcement of the SMTPUTF8 protocol.
644 smtputf8_autodetect_classes (sendmail, verify)
646 Detect that a message requires SMTPUTF8 support for the speci‐
647 fied mail origin classes.
648 Available in Postfix version 3.2 and later:
650 enable_idna2003_compatibility (no)
652 Enable 'transitional' compatibility between IDNA2003 and
653 IDNA2008, when converting UTF-8 domain names to/from the ASCII
654 form that is used for DNS lookups.
655
657 With VERP style delivery, each recipient of a message receives a cus‐
658 tomized copy of the message with his/her own recipient address encoded
659 in the envelope sender address. The VERP_README file describes config‐
660 uration and operation details of Postfix support for variable envelope
661 return path addresses. VERP style delivery is requested with the SMTP
662 XVERP command or with the "sendmail -V" command-line option and is
663 available in Postfix version 1.1 and later.
664 default_verp_delimiters (+=)
666 The two default VERP delimiter characters.
667 verp_delimiter_filter (-=+)
669 The characters Postfix accepts as VERP delimiter characters on
670 the Postfix sendmail(1) command line and in SMTP commands.
671 Available in Postfix version 1.1 and 2.0:
673 authorized_verp_clients ($mynetworks)
675 What remote SMTP clients are allowed to specify the XVERP com‐
676 mand.
677 Available in Postfix version 2.1 and later:
679 smtpd_authorized_verp_clients ($authorized_verp_clients)
681 What remote SMTP clients are allowed to specify the XVERP com‐
682 mand.
683
685 The DEBUG_README document describes how to debug parts of the Postfix
686 mail system. The methods vary from making the software log a lot of de‐
687 tail, to running some daemon processes under control of a call tracer
688 or debugger.
689 debug_peer_level (2)
691 The increment in verbose logging level when a nexthop destina‐
692 tion, remote client or server name or network address matches a
693 pattern given with the debug_peer_list parameter.
694 debug_peer_list (empty)
696 Optional list of nexthop destination, remote client or server
697 name or network address patterns that, if matched, cause the
698 verbose logging level to increase by the amount specified in
699 $debug_peer_level.
700 error_notice_recipient (postmaster)
702 The recipient of postmaster notifications about mail delivery
703 problems that are caused by policy, resource, software or proto‐
704 col errors.
705 internal_mail_filter_classes (empty)
707 What categories of Postfix-generated mail are subject to be‐
708 fore-queue content inspection by non_smtpd_milters,
709 header_checks and body_checks.
710 notify_classes (resource, software)
712 The list of error classes that are reported to the postmaster.
713 smtpd_reject_footer (empty)
715 Optional information that is appended after each Postfix SMTP
716 server 4XX or 5XX response.
717 soft_bounce (no)
719 Safety net to keep mail queued that would otherwise be returned
720 to the sender.
721 Available in Postfix version 2.1 and later:
723 smtpd_authorized_xclient_hosts (empty)
725 What remote SMTP clients are allowed to use the XCLIENT feature.
726 Available in Postfix version 2.10 and later:
728 smtpd_log_access_permit_actions (empty)
730 Enable logging of the named "permit" actions in SMTP server ac‐
731 cess lists (by default, the SMTP server logs "reject" actions
732 but not "permit" actions).
733
735 As of Postfix version 2.0, the SMTP server rejects mail for unknown re‐
736 cipients. This prevents the mail queue from clogging up with undeliver‐
737 able MAILER-DAEMON messages. Additional information on this topic is in
738 the LOCAL_RECIPIENT_README and ADDRESS_CLASS_README documents.
739 show_user_unknown_table_name (yes)
741 Display the name of the recipient table in the "User unknown"
742 responses.
743 canonical_maps (empty)
745 Optional address mapping lookup tables for message headers and
746 envelopes.
747 recipient_canonical_maps (empty)
749 Optional address mapping lookup tables for envelope and header
750 recipient addresses.
751 sender_canonical_maps (empty)
753 Optional address mapping lookup tables for envelope and header
754 sender addresses.
755 Parameters concerning known/unknown local recipients:
757 mydestination ($myhostname, localhost.$mydomain, localhost)
759 The list of domains that are delivered via the $local_transport
760 mail delivery transport.
761 inet_interfaces (all)
763 The network interface addresses that this mail system receives
764 mail on.
765 proxy_interfaces (empty)
767 The network interface addresses that this mail system receives
768 mail on by way of a proxy or network address translation unit.
769 inet_protocols (see 'postconf -d output')
771 The Internet protocols Postfix will attempt to use when making
772 or accepting connections.
773 local_recipient_maps (proxy:unix:passwd.byname $alias_maps)
775 Lookup tables with all names or addresses of local recipients: a
776 recipient address is local when its domain matches $mydestina‐
777 tion, $inet_interfaces or $proxy_interfaces.
778 unknown_local_recipient_reject_code (550)
780 The numerical Postfix SMTP server response code when a recipient
781 address is local, and $local_recipient_maps specifies a list of
782 lookup tables that does not match the recipient.
783 Parameters concerning known/unknown recipients of relay destinations:
785 relay_domains (Postfix >= 3.0: empty, Postfix < 3.0: $mydestination)
787 What destination domains (and subdomains thereof) this system
788 will relay mail to.
789 relay_recipient_maps (empty)
791 Optional lookup tables with all valid addresses in the domains
792 that match $relay_domains.
793 unknown_relay_recipient_reject_code (550)
795 The numerical Postfix SMTP server reply code when a recipient
796 address matches $relay_domains, and relay_recipient_maps speci‐
797 fies a list of lookup tables that does not match the recipient
798 address.
799 Parameters concerning known/unknown recipients in virtual alias do‐
801 mains:
802 virtual_alias_domains ($virtual_alias_maps)
804 Postfix is final destination for the specified list of virtual
805 alias domains, that is, domains for which all addresses are
806 aliased to addresses in other local or remote domains.
807 virtual_alias_maps ($virtual_maps)
809 Optional lookup tables that alias specific mail addresses or do‐
810 mains to other local or remote address.
811 unknown_virtual_alias_reject_code (550)
813 The Postfix SMTP server reply code when a recipient address
814 matches $virtual_alias_domains, and $virtual_alias_maps speci‐
815 fies a list of lookup tables that does not match the recipient
816 address.
817 Parameters concerning known/unknown recipients in virtual mailbox do‐
819 mains:
820 virtual_mailbox_domains ($virtual_mailbox_maps)
822 Postfix is final destination for the specified list of domains;
823 mail is delivered via the $virtual_transport mail delivery
824 transport.
825 virtual_mailbox_maps (empty)
827 Optional lookup tables with all valid addresses in the domains
828 that match $virtual_mailbox_domains.
829 unknown_virtual_mailbox_reject_code (550)
831 The Postfix SMTP server reply code when a recipient address
832 matches $virtual_mailbox_domains, and $virtual_mailbox_maps
833 specifies a list of lookup tables that does not match the recip‐
834 ient address.
835
837 The following parameters limit resource usage by the SMTP server and/or
838 control client request rates.
839 line_length_limit (2048)
841 Upon input, long lines are chopped up into pieces of at most
842 this length; upon delivery, long lines are reconstructed.
843 queue_minfree (0)
845 The minimal amount of free space in bytes in the queue file sys‐
846 tem that is needed to receive mail.
847 message_size_limit (10240000)
849 The maximal size in bytes of a message, including envelope in‐
850 formation.
851 smtpd_recipient_limit (1000)
853 The maximal number of recipients that the Postfix SMTP server
854 accepts per message delivery request.
855 smtpd_timeout (normal: 300s, overload: 10s)
857 The time limit for sending a Postfix SMTP server response and
858 for receiving a remote SMTP client request.
859 smtpd_history_flush_threshold (100)
861 The maximal number of lines in the Postfix SMTP server command
862 history before it is flushed upon receipt of EHLO, RSET, or end
863 of DATA.
864 Available in Postfix version 2.3 and later:
866 smtpd_peername_lookup (yes)
868 Attempt to look up the remote SMTP client hostname, and verify
869 that the name matches the client IP address.
870 The per SMTP client connection count and request rate limits are imple‐
872 mented in co-operation with the anvil(8) service, and are available in
873 Postfix version 2.2 and later.
874 smtpd_client_connection_count_limit (50)
876 How many simultaneous connections any client is allowed to make
877 to this service.
878 smtpd_client_connection_rate_limit (0)
880 The maximal number of connection attempts any client is allowed
881 to make to this service per time unit.
882 smtpd_client_message_rate_limit (0)
884 The maximal number of message delivery requests that any client
885 is allowed to make to this service per time unit, regardless of
886 whether or not Postfix actually accepts those messages.
887 smtpd_client_recipient_rate_limit (0)
889 The maximal number of recipient addresses that any client is al‐
890 lowed to send to this service per time unit, regardless of
891 whether or not Postfix actually accepts those recipients.
892 smtpd_client_event_limit_exceptions ($mynetworks)
894 Clients that are excluded from smtpd_client_*_count/rate_limit
895 restrictions.
896 Available in Postfix version 2.3 and later:
898 smtpd_client_new_tls_session_rate_limit (0)
900 The maximal number of new (i.e., uncached) TLS sessions that a
901 remote SMTP client is allowed to negotiate with this service per
902 time unit.
903 Available in Postfix version 2.9 and later:
905 smtpd_per_record_deadline (normal: no, overload: yes)
907 Change the behavior of the smtpd_timeout and smtpd_start‐
908 tls_timeout time limits, from a time limit per read or write
909 system call, to a time limit to send or receive a complete
910 record (an SMTP command line, SMTP response line, SMTP message
911 content line, or TLS protocol message).
912 Available in Postfix version 3.1 and later:
914 smtpd_client_auth_rate_limit (0)
916 The maximal number of AUTH commands that any client is allowed
917 to send to this service per time unit, regardless of whether or
918 not Postfix actually accepts those commands.
919
921 When a remote SMTP client makes errors, the Postfix SMTP server can in‐
922 sert delays before responding. This can help to slow down run-away
923 software. The behavior is controlled by an error counter that counts
924 the number of errors within an SMTP session that a client makes without
925 delivering mail.
926 smtpd_error_sleep_time (1s)
928 With Postfix version 2.1 and later: the SMTP server response de‐
929 lay after a client has made more than $smtpd_soft_error_limit
930 errors, and fewer than $smtpd_hard_error_limit errors, without
931 delivering mail.
932 smtpd_soft_error_limit (10)
934 The number of errors a remote SMTP client is allowed to make
935 without delivering mail before the Postfix SMTP server slows
936 down all its responses.
937 smtpd_hard_error_limit (normal: 20, overload: 1)
939 The maximal number of errors a remote SMTP client is allowed to
940 make without delivering mail.
941 smtpd_junk_command_limit (normal: 100, overload: 1)
943 The number of junk commands (NOOP, VRFY, ETRN or RSET) that a
944 remote SMTP client can send before the Postfix SMTP server
945 starts to increment the error counter with each junk command.
946 Available in Postfix version 2.1 and later:
948 smtpd_recipient_overshoot_limit (1000)
950 The number of recipients that a remote SMTP client can send in
951 excess of the limit specified with $smtpd_recipient_limit, be‐
952 fore the Postfix SMTP server increments the per-session error
953 count for each excess recipient.
954
956 As of version 2.1, Postfix can be configured to delegate access policy
957 decisions to an external server that runs outside Postfix. See the
958 file SMTPD_POLICY_README for more information.
959 smtpd_policy_service_max_idle (300s)
961 The time after which an idle SMTPD policy service connection is
962 closed.
963 smtpd_policy_service_max_ttl (1000s)
965 The time after which an active SMTPD policy service connection
966 is closed.
967 smtpd_policy_service_timeout (100s)
969 The time limit for connecting to, writing to, or receiving from
970 a delegated SMTPD policy server.
971 Available in Postfix version 3.0 and later:
973 smtpd_policy_service_default_action (451 4.3.5 Server configuration
975 problem)
976 The default action when an SMTPD policy service request fails.
977 smtpd_policy_service_request_limit (0)
979 The maximal number of requests per SMTPD policy service connec‐
980 tion, or zero (no limit).
981 smtpd_policy_service_try_limit (2)
983 The maximal number of attempts to send an SMTPD policy service
984 request before giving up.
985 smtpd_policy_service_retry_delay (1s)
987 The delay between attempts to resend a failed SMTPD policy ser‐
988 vice request.
989 Available in Postfix version 3.1 and later:
991 smtpd_policy_service_policy_context (empty)
993 Optional information that the Postfix SMTP server specifies in
994 the "policy_context" attribute of a policy service request
995 (originally, to share the same service endpoint among multiple
996 check_policy_service clients).
997
999 The SMTPD_ACCESS_README document gives an introduction to all the SMTP
1000 server access control features.
1001 smtpd_delay_reject (yes)
1003 Wait until the RCPT TO command before evaluating
1004 $smtpd_client_restrictions, $smtpd_helo_restrictions and
1005 $smtpd_sender_restrictions, or wait until the ETRN command be‐
1006 fore evaluating $smtpd_client_restrictions and $smtpd_helo_re‐
1007 strictions.
1008 parent_domain_matches_subdomains (see 'postconf -d' output)
1010 A list of Postfix features where the pattern "example.com" also
1011 matches subdomains of example.com, instead of requiring an ex‐
1012 plicit ".example.com" pattern.
1013 smtpd_client_restrictions (empty)
1015 Optional restrictions that the Postfix SMTP server applies in
1016 the context of a client connection request.
1017 smtpd_helo_required (no)
1019 Require that a remote SMTP client introduces itself with the
1020 HELO or EHLO command before sending the MAIL command or other
1021 commands that require EHLO negotiation.
1022 smtpd_helo_restrictions (empty)
1024 Optional restrictions that the Postfix SMTP server applies in
1025 the context of a client HELO command.
1026 smtpd_sender_restrictions (empty)
1028 Optional restrictions that the Postfix SMTP server applies in
1029 the context of a client MAIL FROM command.
1030 smtpd_recipient_restrictions (see 'postconf -d' output)
1032 Optional restrictions that the Postfix SMTP server applies in
1033 the context of a client RCPT TO command, after smtpd_relay_re‐
1034 strictions.
1035 smtpd_etrn_restrictions (empty)
1037 Optional restrictions that the Postfix SMTP server applies in
1038 the context of a client ETRN command.
1039 allow_untrusted_routing (no)
1041 Forward mail with sender-specified routing (user[@%!]re‐
1042 mote[@%!]site) from untrusted clients to destinations matching
1043 $relay_domains.
1044 smtpd_restriction_classes (empty)
1046 User-defined aliases for groups of access restrictions.
1047 smtpd_null_access_lookup_key (<>)
1049 The lookup key to be used in SMTP access(5) tables instead of
1050 the null sender address.
1051 permit_mx_backup_networks (empty)
1053 Restrict the use of the permit_mx_backup SMTP access feature to
1054 only domains whose primary MX hosts match the listed networks.
1055 Available in Postfix version 2.0 and later:
1057 smtpd_data_restrictions (empty)
1059 Optional access restrictions that the Postfix SMTP server ap‐
1060 plies in the context of the SMTP DATA command.
1061 smtpd_expansion_filter (see 'postconf -d' output)
1063 What characters are allowed in $name expansions of RBL reply
1064 templates.
1065 Available in Postfix version 2.1 and later:
1067 smtpd_reject_unlisted_sender (no)
1069 Request that the Postfix SMTP server rejects mail from unknown
1070 sender addresses, even when no explicit reject_unlisted_sender
1071 access restriction is specified.
1072 smtpd_reject_unlisted_recipient (yes)
1074 Request that the Postfix SMTP server rejects mail for unknown
1075 recipient addresses, even when no explicit reject_unlisted_re‐
1076 cipient access restriction is specified.
1077 Available in Postfix version 2.2 and later:
1079 smtpd_end_of_data_restrictions (empty)
1081 Optional access restrictions that the Postfix SMTP server ap‐
1082 plies in the context of the SMTP END-OF-DATA command.
1083 Available in Postfix version 2.10 and later:
1085 smtpd_relay_restrictions (permit_mynetworks, permit_sasl_authenticated,
1087 defer_unauth_destination)
1088 Access restrictions for mail relay control that the Postfix SMTP
1089 server applies in the context of the RCPT TO command, before
1090 smtpd_recipient_restrictions.
1091
1093 Postfix version 2.1 introduces sender and recipient address verifica‐
1094 tion. This feature is implemented by sending probe email messages that
1095 are not actually delivered. This feature is requested via the re‐
1096 ject_unverified_sender and reject_unverified_recipient access restric‐
1097 tions. The status of verification probes is maintained by the ver‐
1098 ify(8) server. See the file ADDRESS_VERIFICATION_README for informa‐
1099 tion about how to configure and operate the Postfix sender/recipient
1100 address verification service.
1101 address_verify_poll_count (normal: 3, overload: 1)
1103 How many times to query the verify(8) service for the completion
1104 of an address verification request in progress.
1105 address_verify_poll_delay (3s)
1107 The delay between queries for the completion of an address veri‐
1108 fication request in progress.
1109 address_verify_sender ($double_bounce_sender)
1111 The sender address to use in address verification probes; prior
1112 to Postfix 2.5 the default was "postmaster".
1113 unverified_sender_reject_code (450)
1115 The numerical Postfix SMTP server response code when a recipient
1116 address is rejected by the reject_unverified_sender restriction.
1117 unverified_recipient_reject_code (450)
1119 The numerical Postfix SMTP server response when a recipient ad‐
1120 dress is rejected by the reject_unverified_recipient restric‐
1121 tion.
1122 Available in Postfix version 2.6 and later:
1124 unverified_sender_defer_code (450)
1126 The numerical Postfix SMTP server response code when a sender
1127 address probe fails due to a temporary error condition.
1128 unverified_recipient_defer_code (450)
1130 The numerical Postfix SMTP server response when a recipient ad‐
1131 dress probe fails due to a temporary error condition.
1132 unverified_sender_reject_reason (empty)
1134 The Postfix SMTP server's reply when rejecting mail with re‐
1135 ject_unverified_sender.
1136 unverified_recipient_reject_reason (empty)
1138 The Postfix SMTP server's reply when rejecting mail with re‐
1139 ject_unverified_recipient.
1140 unverified_sender_tempfail_action ($reject_tempfail_action)
1142 The Postfix SMTP server's action when reject_unverified_sender
1143 fails due to a temporary error condition.
1144 unverified_recipient_tempfail_action ($reject_tempfail_action)
1146 The Postfix SMTP server's action when reject_unverified_recipi‐
1147 ent fails due to a temporary error condition.
1148 Available with Postfix 2.9 and later:
1150 address_verify_sender_ttl (0s)
1152 The time between changes in the time-dependent portion of ad‐
1153 dress verification probe sender addresses.
1154
1156 The following parameters control numerical SMTP reply codes and/or text
1157 responses.
1158 access_map_reject_code (554)
1160 The numerical Postfix SMTP server response code for an access(5)
1161 map "reject" action.
1162 defer_code (450)
1164 The numerical Postfix SMTP server response code when a remote
1165 SMTP client request is rejected by the "defer" restriction.
1166 invalid_hostname_reject_code (501)
1168 The numerical Postfix SMTP server response code when the client
1169 HELO or EHLO command parameter is rejected by the reject_in‐
1170 valid_helo_hostname restriction.
1171 maps_rbl_reject_code (554)
1173 The numerical Postfix SMTP server response code when a remote
1174 SMTP client request is blocked by the reject_rbl_client, re‐
1175 ject_rhsbl_client, reject_rhsbl_reverse_client, re‐
1176 ject_rhsbl_sender or reject_rhsbl_recipient restriction.
1177 non_fqdn_reject_code (504)
1179 The numerical Postfix SMTP server reply code when a client re‐
1180 quest is rejected by the reject_non_fqdn_helo_hostname, re‐
1181 ject_non_fqdn_sender or reject_non_fqdn_recipient restriction.
1182 plaintext_reject_code (450)
1184 The numerical Postfix SMTP server response code when a request
1185 is rejected by the reject_plaintext_session restriction.
1186 reject_code (554)
1188 The numerical Postfix SMTP server response code when a remote
1189 SMTP client request is rejected by the "reject" restriction.
1190 relay_domains_reject_code (554)
1192 The numerical Postfix SMTP server response code when a client
1193 request is rejected by the reject_unauth_destination recipient
1194 restriction.
1195 unknown_address_reject_code (450)
1197 The numerical response code when the Postfix SMTP server rejects
1198 a sender or recipient address because its domain is unknown.
1199 unknown_client_reject_code (450)
1201 The numerical Postfix SMTP server response code when a client
1202 without valid address <=> name mapping is rejected by the re‐
1203 ject_unknown_client_hostname restriction.
1204 unknown_hostname_reject_code (450)
1206 The numerical Postfix SMTP server response code when the host‐
1207 name specified with the HELO or EHLO command is rejected by the
1208 reject_unknown_helo_hostname restriction.
1209 Available in Postfix version 2.0 and later:
1211 default_rbl_reply (see 'postconf -d' output)
1213 The default Postfix SMTP server response template for a request
1214 that is rejected by an RBL-based restriction.
1215 multi_recipient_bounce_reject_code (550)
1217 The numerical Postfix SMTP server response code when a remote
1218 SMTP client request is blocked by the reject_multi_recipi‐
1219 ent_bounce restriction.
1220 rbl_reply_maps (empty)
1222 Optional lookup tables with RBL response templates.
1223 Available in Postfix version 2.6 and later:
1225 access_map_defer_code (450)
1227 The numerical Postfix SMTP server response code for an access(5)
1228 map "defer" action, including "defer_if_permit" or "defer_if_re‐
1229 ject".
1230 reject_tempfail_action (defer_if_permit)
1232 The Postfix SMTP server's action when a reject-type restriction
1233 fails due to a temporary error condition.
1234 unknown_helo_hostname_tempfail_action ($reject_tempfail_action)
1236 The Postfix SMTP server's action when reject_unknown_helo_host‐
1237 name fails due to a temporary error condition.
1238 unknown_address_tempfail_action ($reject_tempfail_action)
1240 The Postfix SMTP server's action when reject_unknown_sender_do‐
1241 main or reject_unknown_recipient_domain fail due to a temporary
1242 error condition.
1243
1245 config_directory (see 'postconf -d' output)
1246 The default location of the Postfix main.cf and master.cf con‐
1247 figuration files.
1248 daemon_timeout (18000s)
1250 How much time a Postfix daemon process may take to handle a re‐
1251 quest before it is terminated by a built-in watchdog timer.
1252 command_directory (see 'postconf -d' output)
1254 The location of all postfix administrative commands.
1255 double_bounce_sender (double-bounce)
1257 The sender address of postmaster notifications that are gener‐
1258 ated by the mail system.
1259 ipc_timeout (3600s)
1261 The time limit for sending or receiving information over an in‐
1262 ternal communication channel.
1263 mail_name (Postfix)
1265 The mail system name that is displayed in Received: headers, in
1266 the SMTP greeting banner, and in bounced mail.
1267 mail_owner (postfix)
1269 The UNIX system account that owns the Postfix queue and most
1270 Postfix daemon processes.
1271 max_idle (100s)
1273 The maximum amount of time that an idle Postfix daemon process
1274 waits for an incoming connection before terminating voluntarily.
1275 max_use (100)
1277 The maximal number of incoming connections that a Postfix daemon
1278 process will service before terminating voluntarily.
1279 myhostname (see 'postconf -d' output)
1281 The internet hostname of this mail system.
1282 mynetworks (see 'postconf -d' output)
1284 The list of "trusted" remote SMTP clients that have more privi‐
1285 leges than "strangers".
1286 myorigin ($myhostname)
1288 The domain name that locally-posted mail appears to come from,
1289 and that locally posted mail is delivered to.
1290 process_id (read-only)
1292 The process ID of a Postfix command or daemon process.
1293 process_name (read-only)
1295 The process name of a Postfix command or daemon process.
1296 queue_directory (see 'postconf -d' output)
1298 The location of the Postfix top-level queue directory.
1299 recipient_delimiter (empty)
1301 The set of characters that can separate an email address local‐
1302 part, user name, or a .forward file name from its extension.
1303 smtpd_banner ($myhostname ESMTP $mail_name)
1305 The text that follows the 220 status code in the SMTP greeting
1306 banner.
1307 syslog_facility (mail)
1309 The syslog facility of Postfix logging.
1310 syslog_name (see 'postconf -d' output)
1312 A prefix that is prepended to the process name in syslog
1313 records, so that, for example, "smtpd" becomes "prefix/smtpd".
1314 Available in Postfix version 2.2 and later:
1316 smtpd_forbidden_commands (CONNECT, GET, POST)
1318 List of commands that cause the Postfix SMTP server to immedi‐
1319 ately terminate the session with a 221 code.
1320 Available in Postfix version 2.5 and later:
1322 smtpd_client_port_logging (no)
1324 Enable logging of the remote SMTP client port in addition to the
1325 hostname and IP address.
1326 Available in Postfix 3.3 and later:
1328 service_name (read-only)
1330 The master.cf service name of a Postfix daemon process.
1331 Available in Postfix 3.4 and later:
1333 smtpd_reject_footer_maps (empty)
1335 Lookup tables, indexed by the complete Postfix SMTP server 4xx
1336 or 5xx response, with reject footer templates.
1337
1339 anvil(8), connection/rate limiting
1340 cleanup(8), message canonicalization
1341 tlsmgr(8), TLS session and PRNG management
1342 trivial-rewrite(8), address resolver
1343 verify(8), address verification service
1344 postconf(5), configuration parameters
1345 master(5), generic daemon options
1346 master(8), process manager
1347 postlogd(8), Postfix logging
1348 syslogd(8), system logging
1349
1351 Use "postconf readme_directory" or "postconf html_directory" to locate
1352 this information.
1353 ADDRESS_CLASS_README, blocking unknown hosted or relay recipients
1354 ADDRESS_REWRITING_README, Postfix address manipulation
1355 BDAT_README, Postfix CHUNKING support
1356 FILTER_README, external after-queue content filter
1357 LOCAL_RECIPIENT_README, blocking unknown local recipients
1358 MILTER_README, before-queue mail filter applications
1359 SMTPD_ACCESS_README, built-in access policies
1360 SMTPD_POLICY_README, external policy server
1361 SMTPD_PROXY_README, external before-queue content filter
1362 SASL_README, Postfix SASL howto
1363 TLS_README, Postfix STARTTLS howto
1364 VERP_README, Postfix XVERP extension
1365 XCLIENT_README, Postfix XCLIENT extension
1366 XFORWARD_README, Postfix XFORWARD extension
1367
1369 The Secure Mailer license must be distributed with this software.
1370
1372 Wietse Venema
1373 IBM T.J. Watson Research
1374 P.O. Box 704
1375 Yorktown Heights, NY 10598, USA
1376 Wietse Venema
1378 Google, Inc.
1379 111 8th Avenue
1380 New York, NY 10011, USA
1381 SASL support originally by:
1383 Till Franke
1384 SuSE Rhein/Main AG
1385 65760 Eschborn, Germany
1386 TLS support originally by:
1388 Lutz Jaenicke
1389 BTU Cottbus
1390 Allgemeine Elektrotechnik
1391 Universitaetsplatz 3-4
1392 D-03044 Cottbus, Germany
1393 Revised TLS support by:
1395 Victor Duchovni
1396 Morgan Stanley
1397 SMTPD(8)