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10 smtp - Postfix SMTP+LMTP client
16 The Postfix SMTP+LMTP client implements the SMTP and LMTP
17 mail delivery protocols. It processes message delivery
18 requests from the queue manager. Each request specifies a
19 queue file, a sender address, a domain or host to deliver
20 to, and recipient information. This program expects to be
23 The SMTP+LMTP client updates the queue file and marks
24 recipients as finished, or it informs the queue manager
25 that delivery should be tried again at a later time.
27 <a href="defer.8.html"><b>defer</b>(8)</a> or <a href="trace.8.html"><b>trace</b>(8)</a> daemon as appropriate.
29 The SMTP+LMTP client looks up a list of mail exchanger
30 addresses for the destination host, sorts the list by
31 preference, and connects to each listed address until it
32 finds a server that responds.
34 When a server is not reachable, or when mail delivery
35 fails due to a recoverable error condition, the SMTP+LMTP
36 client will try to deliver the mail to an alternate host.
38 After a successful mail transaction, a connection may be
40 may be used by any SMTP+LMTP client for a subsequent
41 transaction.
43 By default, connection caching is enabled temporarily for
44 destinations that have a high volume of mail in the active
45 queue. Connection caching can be enabled permanently for
46 specific destinations.
49 SMTP destinations have the following form:
54 Look up the mail exchangers for the specified
55 domain, and connect to the specified port (default:
61 Look up the address(es) of the specified host, and
67 Connect to the host at the specified address, and
72 LMTP destinations have the following form:
75 Connect to the local UNIX-domain server that is
77 runs chrooted, an absolute pathname is interpreted
78 relative to the Postfix queue directory.
87 Connect to the specified TCP port on the specified
88 local or remote host. If no port is specified, con-
90 If no such service is found, the <b><a href="postconf.5.html#lmtp_tcp_port">lmtp_tcp_port</a></b> con-
91 figuration parameter (default value of 24) will be
92 used. An IPv6 address must be formatted as
96 The SMTP+LMTP client is moderately security-sensitive. It
97 talks to SMTP or LMTP servers and to DNS servers on the
98 network. The SMTP+LMTP client can be run chrooted at fixed
99 low privilege.
109 <a href="http://tools.ietf.org/html/rfc2045">RFC 2045</a> (MIME: Format of Internet Message Bodies)
121 rupted message files are marked so that the queue manager
124 Depending on the setting of the <b><a href="postconf.5.html#notify_classes">notify_classes</a></b> parameter,
125 the postmaster is notified of bounces, protocol problems,
126 and of other trouble.
129 SMTP and LMTP connection caching does not work with TLS.
130 The necessary support for TLS object passivation and re-
131 activation does not exist without closing the session,
132 which defeats the purpose.
134 SMTP and LMTP connection caching assumes that SASL creden-
135 tials are valid for all destinations that map onto the
136 same IP address and TCP port.
139 Before Postfix version 2.3, the LMTP client is a separate
140 program that implements only a subset of the functionality
141 available with SMTP: there is no support for TLS, and con-
142 nections are cached in-process, making it ineffective when
143 the client is used for multiple domains.
146 "mirror" parameter for the equivalent LMTP feature. This
147 document describes only those LMTP-related parameters that
148 aren't simply "mirror" parameters.
150 Changes to <a href="postconf.5.html"><b>main.cf</b></a> are picked up automatically, as <a href="smtp.8.html"><b>smtp</b>(8)</a>
151 processes run for only a limited amount of time. Use the
152 command "<b>postfix reload</b>" to speed up a change.
154 The text below provides only a parameter summary. See
159 Ignore DNS MX lookups that produce no response.
162 Always send EHLO at the start of an SMTP session.
165 Never send EHLO at the start of an SMTP session.
167 <b><a href="postconf.5.html#smtp_defer_if_no_mx_address_found">smtp_defer_if_no_mx_address_found</a> (no)</b>
168 Defer mail delivery when no MX record resolves to
169 an IP address.
172 The maximal length of message header and body lines
173 that Postfix will send via SMTP.
175 <b><a href="postconf.5.html#smtp_pix_workaround_delay_time">smtp_pix_workaround_delay_time</a> (10s)</b>
176 How long the Postfix SMTP client pauses before
177 sending ".<CR><LF>" in order to work around the PIX
178 firewall "<CR><LF>.<CR><LF>" bug.
180 <b><a href="postconf.5.html#smtp_pix_workaround_threshold_time">smtp_pix_workaround_threshold_time</a> (500s)</b>
181 How long a message must be queued before the Post-
182 fix SMTP client turns on the PIX firewall
183 "<CR><LF>.<CR><LF>" bug workaround for delivery
184 through firewalls with "smtp fixup" mode turned on.
186 <b><a href="postconf.5.html#smtp_pix_workarounds">smtp_pix_workarounds</a> (disable_esmtp, delay_dotcrlf)</b>
187 A list that specifies zero or more workarounds for
188 CISCO PIX firewall bugs.
191 Lookup tables, indexed by the remote SMTP server
192 address, with per-destination workarounds for CISCO
193 PIX firewall bugs.
195 <b><a href="postconf.5.html#smtp_quote_rfc821_envelope">smtp_quote_rfc821_envelope</a> (yes)</b>
196 Quote addresses in SMTP MAIL FROM and RCPT TO com-
200 Skip SMTP servers that greet with a 5XX status code
201 (go away, do not try again later).
204 Do not wait for the response to the SMTP QUIT com-
205 mand.
207 Available in Postfix version 2.0 and earlier:
210 Skip SMTP servers that greet with a 4XX status code
211 (go away, try again later).
213 Available in Postfix version 2.2 and later:
215 <b><a href="postconf.5.html#smtp_discard_ehlo_keyword_address_maps">smtp_discard_ehlo_keyword_address_maps</a> (empty)</b>
216 Lookup tables, indexed by the remote SMTP server
217 address, with case insensitive lists of EHLO key-
218 words (pipelining, starttls, auth, etc.) that the
219 Postfix SMTP client will ignore in the EHLO
220 response from a remote SMTP server.
222 <b><a href="postconf.5.html#smtp_discard_ehlo_keywords">smtp_discard_ehlo_keywords</a> (empty)</b>
223 A case insensitive list of EHLO keywords (pipelin-
224 ing, starttls, auth, etc.) that the Postfix SMTP
225 client will ignore in the EHLO response from a
226 remote SMTP server.
229 Optional lookup tables that perform address rewrit-
230 ing in the SMTP client, typically to transform a
231 locally valid address into a globally valid address
232 when sending mail across the Internet.
234 Available in Postfix version 2.2.9 and later:
236 <b><a href="postconf.5.html#smtp_cname_overrides_servername">smtp_cname_overrides_servername</a> (version dependent)</b>
237 Allow DNS CNAME records to override the servername
238 that the Postfix SMTP client uses for logging, SASL
239 password lookup, TLS policy decisions, or TLS cer-
240 tificate verification.
242 Available in Postfix version 2.3 and later:
244 <b><a href="postconf.5.html#lmtp_discard_lhlo_keyword_address_maps">lmtp_discard_lhlo_keyword_address_maps</a> (empty)</b>
245 Lookup tables, indexed by the remote LMTP server
246 address, with case insensitive lists of LHLO key-
247 words (pipelining, starttls, auth, etc.) that the
248 LMTP client will ignore in the LHLO response from a
249 remote LMTP server.
251 <b><a href="postconf.5.html#lmtp_discard_lhlo_keywords">lmtp_discard_lhlo_keywords</a> (empty)</b>
252 A case insensitive list of LHLO keywords (pipelin-
253 ing, starttls, auth, etc.) that the LMTP client
254 will ignore in the LHLO response from a remote LMTP
255 server.
257 Available in Postfix version 2.4.4 and later:
260 When authenticating to a remote SMTP or LMTP server
261 with the default setting "no", send no SASL autho-
262 riZation ID (authzid); send only the SASL authenti-
263 Cation ID (authcid) plus the authcid's password.
265 Available in Postfix version 2.5 and later:
269 SMTP client.
272 Restricted <b><a href="postconf.5.html#mime_header_checks">mime_header_checks</a></b>(5) tables for the
273 Postfix SMTP client.
275 <b><a href="postconf.5.html#smtp_nested_header_checks">smtp_nested_header_checks</a> (empty)</b>
276 Restricted <b><a href="postconf.5.html#nested_header_checks">nested_header_checks</a></b>(5) tables for the
277 Postfix SMTP client.
281 SMTP client.
283 Available in Postfix version 2.6 and later:
286 An optional workaround for routers that break TCP
287 window scaling.
290 Available in Postfix version 2.0 and later:
292 <b><a href="postconf.5.html#disable_mime_output_conversion">disable_mime_output_conversion</a> (no)</b>
294 format.
296 <b><a href="postconf.5.html#mime_boundary_length_limit">mime_boundary_length_limit</a> (2048)</b>
297 The maximal length of MIME multipart boundary
298 strings.
301 The maximal recursion level that the MIME processor
302 will handle.
305 Available in Postfix version 2.1 and later:
308 Send the non-standard XFORWARD command when the
309 Postfix SMTP server EHLO response announces XFOR-
310 WARD support.
314 Enable SASL authentication in the Postfix SMTP
315 client.
318 Optional SMTP client lookup tables with one user-
319 name:password entry per remote hostname or domain,
320 or sender address when sender-dependent authentica-
321 tion is enabled.
323 <b><a href="postconf.5.html#smtp_sasl_security_options">smtp_sasl_security_options</a> (noplaintext, noanonymous)</b>
324 Postfix SMTP client SASL security options; as of
325 Postfix 2.3 the list of available features depends
326 on the SASL client implementation that is selected
329 Available in Postfix version 2.2 and later:
331 <b><a href="postconf.5.html#smtp_sasl_mechanism_filter">smtp_sasl_mechanism_filter</a> (empty)</b>
332 If non-empty, a Postfix SMTP client filter for the
333 remote SMTP server's list of offered SASL mecha-
334 nisms.
336 Available in Postfix version 2.3 and later:
338 <b><a href="postconf.5.html#smtp_sender_dependent_authentication">smtp_sender_dependent_authentication</a> (no)</b>
339 Enable sender-dependent authentication in the Post-
340 fix SMTP client; this is available only with SASL
341 authentication, and disables SMTP connection
342 caching to ensure that mail from different senders
343 will use the appropriate credentials.
346 Implementation-specific information that the Post-
347 fix SMTP client passes through to the SASL plug-in
348 implementation that is selected with
352 The SASL plug-in type that the Postfix SMTP client
353 should use for authentication.
355 Available in Postfix version 2.5 and later:
357 <b><a href="postconf.5.html#smtp_sasl_auth_cache_name">smtp_sasl_auth_cache_name</a> (empty)</b>
358 An optional table to prevent repeated SASL authen-
359 tication failures with the same remote SMTP server
360 hostname, username and password.
363 The maximal age of an <a href="postconf.5.html#smtp_sasl_auth_cache_name">smtp_sasl_auth_cache_name</a>
364 entry before it is removed.
366 <b><a href="postconf.5.html#smtp_sasl_auth_soft_bounce">smtp_sasl_auth_soft_bounce</a> (yes)</b>
367 When a remote SMTP server rejects a SASL authenti-
368 cation request with a 535 reply code, defer mail
369 delivery instead of returning mail as undeliver-
370 able.
373 Detailed information about STARTTLS configuration may be
377 The default SMTP TLS security level for the Postfix
378 SMTP client; when a non-empty value is specified,
379 this overrides the obsolete parameters
380 <a href="postconf.5.html#smtp_use_tls">smtp_use_tls</a>, <a href="postconf.5.html#smtp_enforce_tls">smtp_enforce_tls</a>, and
383 <b><a href="postconf.5.html#smtp_sasl_tls_security_options">smtp_sasl_tls_security_options</a> ($<a href="postconf.5.html#smtp_sasl_security_options">smtp_sasl_secu</a>-</b>
385 The SASL authentication security options that the
386 Postfix SMTP client uses for TLS encrypted SMTP
387 sessions.
390 Time limit for Postfix SMTP client write and read
391 operations during TLS startup and shutdown hand-
392 shake procedures.
395 A file containing CA certificates of root CAs
396 trusted to sign either remote SMTP server certifi-
397 cates or intermediate CA certificates.
400 Directory with PEM format certificate authority
401 certificates that the Postfix SMTP client uses to
402 verify a remote SMTP server certificate.
405 File with the Postfix SMTP client RSA certificate
406 in PEM format.
408 <b><a href="postconf.5.html#smtp_tls_mandatory_ciphers">smtp_tls_mandatory_ciphers</a> (medium)</b>
409 The minimum TLS cipher grade that the Postfix SMTP
410 client will use with mandatory TLS encryption.
413 List of ciphers or cipher types to exclude from the
414 Postfix SMTP client cipher list at all TLS security
415 levels.
417 <b><a href="postconf.5.html#smtp_tls_mandatory_exclude_ciphers">smtp_tls_mandatory_exclude_ciphers</a> (empty)</b>
418 Additional list of ciphers or cipher types to
419 exclude from the SMTP client cipher list at manda-
420 tory TLS security levels.
423 File with the Postfix SMTP client DSA certificate
424 in PEM format.
426 <b><a href="postconf.5.html#smtp_tls_dkey_file">smtp_tls_dkey_file</a> ($<a href="postconf.5.html#smtp_tls_dcert_file">smtp_tls_dcert_file</a>)</b>
427 File with the Postfix SMTP client DSA private key
428 in PEM format.
430 <b><a href="postconf.5.html#smtp_tls_key_file">smtp_tls_key_file</a> ($<a href="postconf.5.html#smtp_tls_cert_file">smtp_tls_cert_file</a>)</b>
431 File with the Postfix SMTP client RSA private key
432 in PEM format.
435 Enable additional Postfix SMTP client logging of
436 TLS activity.
438 <b><a href="postconf.5.html#smtp_tls_note_starttls_offer">smtp_tls_note_starttls_offer</a> (no)</b>
439 Log the hostname of a remote SMTP server that
440 offers STARTTLS, when TLS is not already enabled
441 for that server.
444 Optional lookup tables with the Postfix SMTP client
445 TLS security policy by next-hop destination; when a
446 non-empty value is specified, this overrides the
449 <b><a href="postconf.5.html#smtp_tls_mandatory_protocols">smtp_tls_mandatory_protocols</a> (SSLv3, TLSv1)</b>
450 List of SSL/TLS protocols that the Postfix SMTP
451 client will use with mandatory TLS encryption.
454 The verification depth for remote SMTP server cer-
455 tificates.
457 <b><a href="postconf.5.html#smtp_tls_secure_cert_match">smtp_tls_secure_cert_match</a> (nexthop, dot-nexthop)</b>
458 The server certificate peername verification method
459 for the "secure" TLS security level.
461 <b><a href="postconf.5.html#smtp_tls_session_cache_database">smtp_tls_session_cache_database</a> (empty)</b>
462 Name of the file containing the optional Postfix
463 SMTP client TLS session cache.
465 <b><a href="postconf.5.html#smtp_tls_session_cache_timeout">smtp_tls_session_cache_timeout</a> (3600s)</b>
466 The expiration time of Postfix SMTP client TLS ses-
467 sion cache information.
469 <b><a href="postconf.5.html#smtp_tls_verify_cert_match">smtp_tls_verify_cert_match</a> (hostname)</b>
470 The server certificate peername verification method
471 for the "verify" TLS security level.
475 or <a href="smtpd.8.html"><b>smtpd</b>(8)</a> process requests from the <a href="tlsmgr.8.html"><b>tlsmgr</b>(8)</a>
476 server in order to seed its internal pseudo random
477 number generator (PRNG).
481 The OpenSSL cipherlist for "HIGH" grade ciphers.
483 <b><a href="postconf.5.html#tls_medium_cipherlist">tls_medium_cipherlist</a> (ALL:!EXPORT:!LOW:+RC4:@STRENGTH)</b>
484 The OpenSSL cipherlist for "MEDIUM" or higher grade
485 ciphers.
487 <b><a href="postconf.5.html#tls_low_cipherlist">tls_low_cipherlist</a> (ALL:!EXPORT:+RC4:@STRENGTH)</b>
488 The OpenSSL cipherlist for "LOW" or higher grade
489 ciphers.
491 <b><a href="postconf.5.html#tls_export_cipherlist">tls_export_cipherlist</a> (ALL:+RC4:@STRENGTH)</b>
492 The OpenSSL cipherlist for "EXPORT" or higher grade
493 ciphers.
496 The OpenSSL cipherlist for "NULL" grade ciphers
497 that provide authentication without encryption.
499 Available in Postfix version 2.4 and later:
501 <b><a href="postconf.5.html#smtp_sasl_tls_verified_security_options">smtp_sasl_tls_verified_security_options</a></b>
502 <b>($<a href="postconf.5.html#smtp_sasl_tls_security_options">smtp_sasl_tls_security_options</a>)</b>
503 The SASL authentication security options that the
504 Postfix SMTP client uses for TLS encrypted SMTP
505 sessions with a verified server certificate.
507 Available in Postfix version 2.5 and later:
509 <b><a href="postconf.5.html#smtp_tls_fingerprint_cert_match">smtp_tls_fingerprint_cert_match</a> (empty)</b>
510 List of acceptable remote SMTP server certificate
511 fingerprints for the "fingerprint" TLS security
512 level (<b><a href="postconf.5.html#smtp_tls_security_level">smtp_tls_security_level</a></b> = fingerprint).
514 <b><a href="postconf.5.html#smtp_tls_fingerprint_digest">smtp_tls_fingerprint_digest</a> (md5)</b>
515 The message digest algorithm used to construct
516 remote SMTP server certificate fingerprints.
518 Available in Postfix version 2.6 and later:
521 List of TLS protocols that the Postfix SMTP client
522 will exclude or include with opportunistic TLS
523 encryption.
526 The minimum TLS cipher grade that the Postfix SMTP
527 client will use with opportunistic TLS encryption.
530 File with the Postfix SMTP client ECDSA certificate
531 in PEM format.
533 <b><a href="postconf.5.html#smtp_tls_eckey_file">smtp_tls_eckey_file</a> ($<a href="postconf.5.html#smtp_tls_eccert_file">smtp_tls_eccert_file</a>)</b>
534 File with the Postfix SMTP client ECDSA private key
535 in PEM format.
538 The following configuration parameters exist for compati-
539 bility with Postfix versions before 2.3. Support for these
540 will be removed in a future release.
543 Opportunistic mode: use TLS when a remote SMTP
544 server announces STARTTLS support, otherwise send
545 the mail in the clear.
548 Enforcement mode: require that remote SMTP servers
549 use TLS encryption, and never send mail in the
550 clear.
553 With mandatory TLS encryption, require that the
554 remote SMTP server hostname matches the information
555 in the remote SMTP server certificate.
558 Optional lookup tables with the Postfix SMTP client
559 TLS usage policy by next-hop destination and by
560 remote SMTP server hostname.
564 client TLS cipher list.
567 <b><a href="postconf.5.html#smtp_destination_concurrency_limit">smtp_destination_concurrency_limit</a> ($<a href="postconf.5.html#default_destination_concurrency_limit">default_destina</a>-</b>
568 <b><a href="postconf.5.html#default_destination_concurrency_limit">tion_concurrency_limit</a>)</b>
569 The maximal number of parallel deliveries to the
570 same destination via the smtp message delivery
571 transport.
573 <b><a href="postconf.5.html#smtp_destination_recipient_limit">smtp_destination_recipient_limit</a> ($<a href="postconf.5.html#default_destination_recipient_limit">default_destina</a>-</b>
575 The maximal number of recipients per message for
576 the smtp message delivery transport.
579 The SMTP client time limit for completing a TCP
580 connection, or zero (use the operating system
581 built-in time limit).
584 The SMTP client time limit for sending the HELO or
585 EHLO command, and for receiving the initial server
586 response.
589 The LMTP client time limit for sending the LHLO
590 command, and for receiving the initial server
591 response.
594 The SMTP client time limit for sending the XFORWARD
595 command, and for receiving the server response.
598 The SMTP client time limit for sending the MAIL
599 FROM command, and for receiving the server
600 response.
603 The SMTP client time limit for sending the SMTP
604 RCPT TO command, and for receiving the server
605 response.
608 The SMTP client time limit for sending the SMTP
609 DATA command, and for receiving the server
610 response.
613 The SMTP client time limit for sending the SMTP
614 message content.
617 The SMTP client time limit for sending the SMTP
618 ".", and for receiving the server response.
621 The SMTP client time limit for sending the QUIT
622 command, and for receiving the server response.
624 Available in Postfix version 2.1 and later:
627 The maximal number of MX (mail exchanger) IP
628 addresses that can result from mail exchanger
629 lookups, or zero (no limit).
632 The maximal number of SMTP sessions per delivery
633 request before giving up or delivering to a fall-
637 The SMTP client time limit for sending the RSET
638 command, and for receiving the server response.
640 Available in Postfix version 2.2 and earlier:
643 Keep Postfix LMTP client connections open for up to
646 Available in Postfix version 2.2 and later:
648 <b><a href="postconf.5.html#smtp_connection_cache_destinations">smtp_connection_cache_destinations</a> (empty)</b>
649 Permanently enable SMTP connection caching for the
650 specified destinations.
652 <b><a href="postconf.5.html#smtp_connection_cache_on_demand">smtp_connection_cache_on_demand</a> (yes)</b>
653 Temporarily enable SMTP connection caching while a
654 destination has a high volume of mail in the active
655 queue.
657 <b><a href="postconf.5.html#smtp_connection_reuse_time_limit">smtp_connection_reuse_time_limit</a> (300s)</b>
658 The amount of time during which Postfix will use an
659 SMTP connection repeatedly.
661 <b><a href="postconf.5.html#smtp_connection_cache_time_limit">smtp_connection_cache_time_limit</a> (2s)</b>
662 When SMTP connection caching is enabled, the amount
663 of time that an unused SMTP client socket is kept
664 open before it is closed.
666 Available in Postfix version 2.3 and later:
668 <b><a href="postconf.5.html#connection_cache_protocol_timeout">connection_cache_protocol_timeout</a> (5s)</b>
669 Time limit for connection cache connect, send or
670 receive operations.
674 The increment in verbose logging level when a
675 remote client or server matches a pattern in the
679 Optional list of remote client or server hostname
680 or network address patterns that cause the verbose
681 logging level to increase by the amount specified
685 The recipient of postmaster notifications about
686 mail delivery problems that are caused by policy,
687 resource, software or protocol errors.
689 <b><a href="postconf.5.html#internal_mail_filter_classes">internal_mail_filter_classes</a> (empty)</b>
690 What categories of Postfix-generated mail are sub-
691 ject to before-queue content inspection by
692 <a href="postconf.5.html#non_smtpd_milters">non_smtpd_milters</a>, <a href="postconf.5.html#header_checks">header_checks</a> and <a href="postconf.5.html#body_checks">body_checks</a>.
695 The list of error classes that are reported to the
696 postmaster.
700 Where the Postfix SMTP client should deliver mail
701 when it detects a "mail loops back to myself" error
702 condition.
704 <b><a href="postconf.5.html#config_directory">config_directory</a> (see 'postconf -d' output)</b>
709 How much time a Postfix daemon process may take to
710 handle a request before it is terminated by a
711 built-in watchdog timer.
713 <b><a href="postconf.5.html#delay_logging_resolution_limit">delay_logging_resolution_limit</a> (2)</b>
714 The maximal number of digits after the decimal
715 point when logging sub-second delay values.
718 Disable DNS lookups in the Postfix SMTP and LMTP
719 clients.
722 The network interface addresses that this mail sys-
723 tem receives mail on.
726 The Internet protocols Postfix will attempt to use
727 when making or accepting connections.
730 The time limit for sending or receiving information
731 over an internal communication channel.
734 When an LMTP server announces no DSN support,
735 assume that the server performs final delivery, and
736 send "delivered" delivery status notifications
737 instead of "relayed".
740 The default TCP port that the Postfix LMTP client
741 connects to.
744 The maximum amount of time that an idle Postfix
745 daemon process waits for an incoming connection
746 before terminating voluntarily.
749 The maximal number of incoming connections that a
750 Postfix daemon process will service before termi-
751 nating voluntarily.
754 The process ID of a Postfix command or daemon
755 process.
758 The process name of a Postfix command or daemon
759 process.
762 The network interface addresses that this mail sys-
763 tem receives mail on by way of a proxy or network
764 address translation unit.
767 An optional numerical network address that the
768 Postfix SMTP client should bind to when making an
769 IPv4 connection.
772 An optional numerical network address that the
773 Postfix SMTP client should bind to when making an
774 IPv6 connection.
776 <b><a href="postconf.5.html#smtp_helo_name">smtp_helo_name</a> ($<a href="postconf.5.html#myhostname">myhostname</a>)</b>
777 The hostname to send in the SMTP EHLO or HELO com-
778 mand.
780 <b><a href="postconf.5.html#lmtp_lhlo_name">lmtp_lhlo_name</a> ($<a href="postconf.5.html#myhostname">myhostname</a>)</b>
781 The hostname to send in the LMTP LHLO command.
784 What mechanisms when the Postfix SMTP client uses
785 to look up a host's IP address.
788 Randomize the order of equal-preference MX host
789 addresses.
792 The syslog facility of Postfix logging.
795 The mail system name that is prepended to the
796 process name in syslog records, so that "smtpd"
797 becomes, for example, "postfix/smtpd".
799 Available with Postfix 2.2 and earlier:
802 Optional list of relay hosts for SMTP destinations
803 that can't be found or that are unreachable.
805 Available with Postfix 2.3 and later:
807 <b><a href="postconf.5.html#smtp_fallback_relay">smtp_fallback_relay</a> ($<a href="postconf.5.html#fallback_relay">fallback_relay</a>)</b>
808 Optional list of relay hosts for SMTP destinations
809 that can't be found or that are unreachable.
822 syslogd(8), system logging
829 The Secure Mailer license must be distributed with this
830 software.
833 Wietse Venema
834 IBM T.J. Watson Research
835 P.O. Box 704
836 Yorktown Heights, NY 10598, USA
838 Command pipelining in cooperation with:
839 Jon Ribbens
840 Oaktree Internet Solutions Ltd.,
841 Internet House,
842 Canal Basin,
843 Coventry,
844 CV1 4LY, United Kingdom.
846 SASL support originally by:
847 Till Franke
848 SuSE Rhein/Main AG
849 65760 Eschborn, Germany
851 TLS support originally by:
852 Lutz Jaenicke
853 BTU Cottbus
854 Allgemeine Elektrotechnik
856 D-03044 Cottbus, Germany
858 Revised TLS and SMTP connection cache support by:
859 Victor Duchovni
860 Morgan Stanley
862 SMTP(8)
863 </pre> </body> </html>