#
281658b6 |
| 08-Oct-2022 |
christos <christos@NetBSD.org> |
Import Postfix-3.7.3 (previous version was 3.5.2)
This is the Postfix 3.7 (stable) release.
The stable Postfix release is called postfix-3.7.x where 3=major release number, 7=minor release number,
Import Postfix-3.7.3 (previous version was 3.5.2)
This is the Postfix 3.7 (stable) release.
The stable Postfix release is called postfix-3.7.x where 3=major release number, 7=minor release number, x=patchlevel. The stable release never changes except for patches that address bugs or emergencies. Patches change the patchlevel and the release date.
New features are developed in snapshot releases. These are called postfix-3.8-yyyymmdd where yyyymmdd is the release date (yyyy=year, mm=month, dd=day). Patches are never issued for snapshot releases; instead, a new snapshot is released.
The mail_release_date configuration parameter (format: yyyymmdd) specifies the release date of a stable release or snapshot release.
If you upgrade from Postfix 3.5 or earlier, read RELEASE_NOTES-3.6 before proceeding.
License change ---------------
This software is distributed with a dual license: in addition to the historical IBM Public License 1.0, it is now also distributed with the more recent Eclipse Public License 2.0. Recipients can choose to take the software under the license of their choice. Those who are more comfortable with the IPL can continue with that license.
Bugfix for messages not delivered after "warning: Unexpected record type 'X' ============================================================================
Due to a bug introduced in Postfix 3.7.0, a message could falsely be flagged as corrupt with "warning: Unexpected record type 'X'".
Such messages were moved to the "corrupt" queue directory, where they may still be found. See below for instructions to deal with these falsely flagged messages.
This could happen for messages with 5000 or more recipients, or with fewer recipients on a busy mail server. The problem was first reported by Frank Brendel, reproduced by John Alex.
A file in the "corrupt" queue directory may be inspected with the command "postcat /var/spool/postfix/corrupt/<filename>. If delivery of the file is still desired, the file can be moved back to /var/spool/postfix/incoming after updating Postfix and executing "postfix reload".
Major changes - configuration -----------------------------
[Feature 20210605] Support to inline the content of small cidr:, pcre:, and regexp: tables in Postfix parameter values.
Example:
smtpd_forbidden_commands = CONNECT GET POST regexp:{{/^[^A-Z]/ Thrash}}
This is the new smtpd_forbidden_commands default value. It will immediately disconnect a remote SMTP client when a command does not start with a letter (a-z or A-Z).
The basic syntax is:
/etc/postfix/main.cf: parameter = .. map-type:{ { rule-1 }, { rule-2 } .. } ..
/etc/postfix/master.cf: .. -o { parameter = .. map-type:{ { rule-1 }, { rule-2 } .. } .. } ..
where map-type is one of cidr, pcre, or regexp.
Postfix ignores whitespace after '{' and before '}', and writes each rule as one text line to a nameless in-memory file:
in-memory file: rule-1 rule-2 ..
Postfix parses the result as if it is a file in /etc/postfix.
Note: if a rule contains $, specify $$ to keep Postfix from trying to do $name expansion as it evaluates the parameter value.
Major changes - lmdb support ----------------------------
[Feature 20210605] Overhauled the LMDB client's error handling, and added integration tests for future-proofing. There are no visible changes in documented behavior.
Major changes - logging -----------------------
[Feature 20210815] To make the maillog_file feature more useful, the postlog(1) command is now set-gid postdrop, so that unprivileged programs can use it to write logging through the postlogd(8) daemon. This required hardening the postlog(1) command against privilege escalation attacks. DO NOT turn on the set-gid bit with older postlog(1) implementations.
Major changes - pcre2 support -----------------------------
[Feature 20211127] Support for the pcre2 library (the legacy pcre library is no longer maintained). The Postfix build procedure automatically detects if the pcre2 library is installed, and if it is unavailable, the Postfix build procedure will detect if the legacy pcre library is installed. See PCRE_README if you need to build Postfix with a specific library.
Visible differences: some error messages may have a different text, and the 'X' pattern flag is no longer supported with pcre2.
Major changes - security ------------------------
[Feature 20220102] Postfix programs now randomize the initial state of in-memory hash tables, to defend against hash collision attacks involving a large number of attacker-chosen lookup keys. Presently, the only known opportunity for such attacks involves remote SMTP client IPv6 addresses in the anvil(8) service. The attack would require making hundreds of short-lived connections per second from thousands of different IP addresses, because the anvil(8) service drops inactive counters after 100s. Other in-memory hash tables with attacker-chosen lookup keys are by design limited in size. The fix is cheap, and therefore implemented for all Postfix in-memory hash tables. Problem reported by Pascal Junod.
[Feature 20211030] The postqueue command now sanitizes non-printable characters (such as newlines) in strings before they are formatted as json or as legacy output. These outputs are piped into other programs that are run by administrative users. This closes a hypothetical opportunity for privilege escalation.
[Feature 20210815] Updated defense against remote clients or servers that 'trickle' SMTP or LMTP traffic, based on per-request deadlines and minimum data rates.
Per-request deadlines:
The new {smtpd,smtp,lmtp}_per_request_deadline parameters replace {smtpd,smtp,lmtp}_per_record_deadline, with backwards compatible default settings. This defense is enabled by default in the Postfix SMTP server in case of overload.
The new smtpd_per_record_deadline parameter limits the combined time for the Postfix SMTP server to receive a request and to send a response, while the new {smtp,lmtp}_per_record_deadline parameters limit the combined time for the Postfix SMTP or LMTP client to send a request and to receive a response.
Minimum data rates:
The new smtpd_min_data_rate parameter enforces a minimum plaintext data transfer rate for DATA and BDAT requests, but only when smtpd_per_record_deadline is enabled. After a read operation transfers N plaintext bytes (possibly after TLS decryption), and after the DATA or BDAT request deadline is decreased by the elapsed time of that read operation, the DATA or BDAT request deadline is increased by N/smtpd_min_data_rate seconds. However, the deadline is never increased beyond the smtpd_timeout value. The default minimum data rate is 500 (bytes/second) but is still subject to change.
The new {smtp,lmtp}_min_data_rate parameters enforce the corresponding minimum DATA transfer rates for the Postfix SMTP and LMTP client.
Major changes - tls support ---------------------------
[Cleanup 20220121] The new tlsproxy_client_security_level parameter replaces tlsproxy_client_level, and the new tlsproxy_client_policy_maps parameter replaces tlsproxy_client_policy. This is for consistent parameter naming (tlsproxy_client_xxx corresponds to smtp_tls_xxx). This change was made with backwards-compatible default settings.
[Feature 20210926] Postfix was updated to support OpenSSL 3.0.0 API features, and to work around OpenSSL 3.0.0 bit-rot (avoid using deprecated API features).
Other code health -----------------
[typos] Typo fixes by raf.
[pre-release checks] Added pre-release checks to detect a) new typos in documentation and source-code comments, b) missing entries in the postfix-files file (some documentation would not be installed), c) missing rules in the postlink script (some text would not have a hyperlink in documentation), and d) missing map-based $parameter names in the proxy_read_maps default value (the proxymap daemon would not automatically authorize some proxied maps).
[memory stream] Improved support for memory-based streams made it possible to inline small cidr:, pcre:, and regexp: maps in Postfix parameter values, and to eliminate some ad-hoc code that converted tlsproxy(8) protocol data to or from serialized form.
*************************************************************************
This is the Postfix 3.6 (stable) release.
The stable Postfix release is called postfix-3.6.x where 3=major release number, 6=minor release number, x=patchlevel. The stable release never changes except for patches that address bugs or emergencies. Patches change the patchlevel and the release date.
New features are developed in snapshot releases. These are called postfix-3.7-yyyymmdd where yyyymmdd is the release date (yyyy=year, mm=month, dd=day). Patches are never issued for snapshot releases; instead, a new snapshot is released.
The mail_release_date configuration parameter (format: yyyymmdd) specifies the release date of a stable release or snapshot release.
If you upgrade from Postfix 3.4 or earlier, read RELEASE_NOTES-3.5 before proceeding.
License change ---------------
This software is distributed with a dual license: in addition to the historical IBM Public License 1.0, it is now also distributed with the more recent Eclipse Public License 2.0. Recipients can choose to take the software under the license of their choice. Those who are more comfortable with the IPL can continue with that license.
Major changes - internal protocol identification ------------------------------------------------
[Incompat 20200920] Internal protocols have changed. You need to "postfix stop" before updating, or before backing out to an earlier release, otherwise long-running daemons (pickup, qmgr, verify, tlsproxy, postscreen) may fail to communicate with the rest of Postfix, causing mail delivery delays until Postfix is restarted.
This change does not affect message files in Postfix queue directories, only the communication between running Postfix programs.
With this change, every Postfix internal service, including the postdrop command, announces the name of its protocol before doing any other I/O. Every Postfix client program, including the Postfix sendmail command, will verify that the protocol name matches what it is supposed to be.
The purpose of this change is to produce better error messages, for example, when someone configures the discard daemon as a bounce service in master.cf, or vice versa.
This change may break third-party programs that implement a Postfix-internal protocol such as qpsmtpd. Such programs have never been supported. Fortunately, this will be an easy fix: look at the first data from the cleanup daemon: if it is a protocol announcement, you're talking to Postfix 3.6 or later. That's the only real change.
Major changes - tls -------------------
[Incompat 20200705] The minimum supported OpenSSL version is 1.1.1, which will reach the end of life by 2023-09-11. Postfix 3.6 is expected to reach the end of support in 2025. Until then, Postfix will be updated as needed for compatibility with OpenSSL.
The default fingerprint digest has changed from md5 to sha256 (Postfix 3.6 with compatibility_level >= 3.6). With a lower compatibility_level setting, Postfix defaults to using md5, and logs a warning when a Postfix configuration specifies no explicit digest type.
Export-grade Diffie-Hellman key exchange is no longer supported, and the tlsproxy_tls_dh512_param_file parameter is ignored,
[Feature 20200906] The tlstype.pl helper script by Viktor Dukhovni reports TLS information per message delivery. This processes output from the collate.pl script. See auxiliary/collate/README.tlstype and auxiliary/collate/tlstype.pl.
Major changes - compatibility level -----------------------------------
[Feature 20210109] Starting with Postfix version 3.6, the compatibility level is "3.6". In future Postfix releases, the compatibility level will be the Postfix version that introduced the last incompatible change. The level is formatted as 'major.minor.patch', where 'patch' is usually omitted and defaults to zero. Earlier compatibility levels are 0, 1 and 2.
This also introduces main.cf and master.cf support for the <=level, <level, and other operators to compare compatibility levels. With the standard <=, <, etc. operators, compatibility level 3.10 would be less than 3.9, which is undesirable.
Major changes - services(5) override ------------------------------------
[Feature 20210418] Postfix no longer uses the services(5) database to look up the TCP ports for SMTP and LMTP services. Instead, this information is configured with the new known_tcp_ports configuration parameter (default: lmtp=24, smtp=25, smtps=submissions=465, submission=587). When a service is not specified in known_tcp_ports, Postfix will still query the services(5) database.
Major changes - local_login_sender_maps ---------------------------------------
[Feature 20201025] Fine-grained control over the envelope sender address for submission with the Postfix sendmail (or postdrop) commands.
The local_login_sender_maps parameter (default: static:*) specifies a list of lookup tables that are searched by the UNIX login name, and that return a list of allowed envelope sender patterns separated by space or comma. The default is backwards-compatible: every user may specify any sender envelope address.
This feature is enforced by the postdrop command. When no UNIX login name is available, the postdrop command will prepend "uid:" to the numerical UID and use that instead.
This feature ignores address extensions in the user-specified envelope sender address.
Besides the special pattern "*" which allows any sender address, there are "<>" which matches an empty sender address, and the "@domain" wildcard pattern. More information about those can be found in the postconf(5) manpage.
Example:
/etc/postfix/main.cf: # Allow root and postfix full control, anyone else can only # send mail as themselves. Use "uid:" followed by the numerical # UID when the UID has no entry in the UNIX password file. local_login_sender_maps = inline:{ { root = *}, { postfix = * } }, pcre:/etc/postfix/login_senders
/etc/postfix/login_senders: # Allow both the bare username and the user@domain forms. /(.+)/ $1 $1@example.com
Major changes - order of relay and recipient restrictions ---------------------------------------------------------
[Incompat 20210131] With smtpd_relay_before_recipient_restrictions=yes, the Postfix SMTP server will evaluate smtpd_relay_restrictions before smtpd_recipient_restrictions. This is the default behavior with compatibility_level >= 3.6.
This change makes the implemented behavior consistent with existing documentation. There is a backwards-compatibility warning that allows users to freeze historical behavior. See COMPATIBILITY_README for details.
Major changes - respectful logging ----------------------------------
[Feature 20210220] Postfix version 3.6 deprecates terminology that implies white is better than black. Instead, Postfix prefers 'allowlist', 'denylist', and variations on those words. This change affects Postfix documentation, and postscreen parameters and logging.
To keep the old postscreen logging set "respectful_logging = no" in main.cf.
Noel Jones assisted with the initial transition.
Changes in documentation ------------------------
Postfix documentation was updated to use 'allowlist', 'denylist', etc. These documentation changes do not affect Postfix behavior.
Changes in parameter names --------------------------
The following postscreen parameters replace names that contain 'blacklist' or 'whitelist':
postscreen_allowlist_interfaces postscreen_denylist_action postscreen_dnsbl_allowlist_threshold
These new parameters have backwards-compatible default settings that support the old parameter names, so that the name change should not affect Postfix behavior. This means that existing management tools that use the old parameter names should keep working as before.
This compatibility safety net may break when some management tools use the new parameter names, and some use the old names, such that different tools will disagree on how Postfix works.
Changes in logging ------------------
The following logging replaces forms that contain 'blacklist' or 'whitelist':
postfix/postscreen[pid]: ALLOWLIST VETO [address]:port postfix/postscreen[pid]: ALLOWLISTED [address]:port postfix/postscreen[pid]: DENYLISTED [address]:port
To avoid breaking logfile analysis tools, Postfix keeps logging the old forms by default, as long as the compatibility_level parameter setting is less than 3.6, and the respectful_logging parameter is not explicitly configured. As a reminder, Postfix will log the following:
postfix/postscreen[pid]: Using backwards-compatible default setting respectful_logging=no for client [address]:port
To keep logging the old form, make the setting "respectful_logging = no" permanent in main.cf, for example:
# postconf "respectful_logging = no" # postfix reload
To stop the reminder, configure the respectful_logging parameter to "yes" or "no", or configure "compatibility_level = 3.6".
Major changes - threaded bounces --------------------------------
[Feature 20201205] Support for threaded bounces. This allows mail readers to present a non-delivery, delayed delivery, or successful delivery notification in the same email thread as the original message.
Unfortunately, this also makes it easy for users to mistakenly delete the whole email thread (all related messages), instead of deleting only the delivery status notification.
To enable, specify "enable_threaded_bounces = yes".
Other changes - smtpd_sasl_mechanism_list -----------------------------------------
[Feature 20200906] The smtpd_sasl_mechanism_list parameter (default: !external, static:rest) prevents confusing errors when a SASL backend announces EXTERNAL support which Postfix does not support.
Other changes - delivery logging --------------------------------
[Incompat 20200531] Postfix delivery agents now log an explicit record when delegating delivery to a different Postfix delivery agent.
For example, with "best_mx_transport = local", an SMTP delivery agent will now log when a recipient will be delivered locally. This makes the delegating delivery agent visible, where it would otherwise have remained invisible, which would complicate troubleshooting.
postfix/smtp[pid]: queueid: passing <recipient> to transport=local
This will usually be followed by logging for an actual delivery:
postfix/local[pid]: queueid: to=<recipient>, relay=local, ...
Other examples: the local delivery agent will log a record that it defers mailbox delivery through mailbox_transport or through fallback_transport.
Other changes - error logging -----------------------------
[Incompat 20200531] Postfix programs will now log "Application error" instead of "Success" or "Unknown error: 0" when an operation fails with errno == 0, i.e., the error originates from non-kernel code.
Other changes - dns lookups ---------------------------
[Feature 20200509] The threadsafe resolver API (res_nxxx() calls) is now the default, not because the API is threadsafe, but because this is the API where new features are being added.
To build old style, build with:
make makefiles CCARGS="-DNO_RES_NCALLS..."
This is the default for systems that are known not to support the threadsafe resolver API.
show more ...
|
#
e09e275d |
| 18-Mar-2020 |
christos <christos@NetBSD.org> |
This is the Postfix 3.5 (stable) release.
The stable Postfix release is called postfix-3.5.x where 3=major release number, 5=minor release number, x=patchlevel. The stable release never changes exc
This is the Postfix 3.5 (stable) release.
The stable Postfix release is called postfix-3.5.x where 3=major release number, 5=minor release number, x=patchlevel. The stable release never changes except for patches that address bugs or emergencies. Patches change the patchlevel and the release date.
New features are developed in snapshot releases. These are called postfix-3.6-yyyymmdd where yyyymmdd is the release date (yyyy=year, mm=month, dd=day). Patches are never issued for snapshot releases; instead, a new snapshot is released.
The mail_release_date configuration parameter (format: yyyymmdd) specifies the release date of a stable release or snapshot release.
If you upgrade from Postfix 3.3 or earlier, read RELEASE_NOTES-3.4 before proceeding.
License change ---------------
This software is distributed with a dual license: in addition to the historical IBM Public License 1.0, it is now also distributed with the more recent Eclipse Public License 2.0. Recipients can choose to take the software under the license of their choice. Those who are more comfortable with the IPL can continue with that license.
Major changes - multiple relayhost in SMTP ------------------------------------------
[Feature 20200111] the Postfix SMTP and LMTP client support a list of nexthop destinations separated by comma or whitespace. These destinations will be tried in the specified order.
The list form can be specified in relayhost, transport_maps, default_transport, and sender_dependent_default_transport_maps.
Examples: /etc/postfix/main.cf: relayhost = foo.example, bar.example default_transport = smtp:foo.example, bar.example.
NOTE: this is an SMTP and LMTP client feature. It does not work for other Postfix delivery agents.
Major changes - certificate access ----------------------------------
[Feature 20190517] Search order support for check_ccert_access. Search order support for other tables is in design (canonical_maps, virtual_alias_maps, transport_maps, etc.).
The following check_ccert_access setting uses the built-in search order: it first looks up the client certificate fingerprint, then the client certificate public-key fingerprint, and it stops when a decision is made.
/etc/postfix/main.cf: smtpd_mumble_restrictions = ... check_ccert_access hash:/etc/postfix/ccert-access ...
The following setting, with explicit search order, produces the exact same result:
/etc/postfix/main.cf: smtpd_mumble_restrictions = ... check_ccert_access { hash:/etc/postfix/ccert-access { search_order = cert_fingerprint, pubkey_fingerprint } } ...
Support is planned for other certificate features.
Major changes - dovecot usability ---------------------------------
[Feature 20190615] The SMTP+LMTP delivery agent can now prepend Delivered-To, X-Original-To and Return-Path headers, just like the pipe(8) and local(8) delivery agents.
This uses the "flags=DORX" command-line flags in master.cf. See the smtp(8) manpage for details.
This obsoletes the "lmtp_assume_final = yes" setting, and replaces it with "flags=...X...", for consistency with the pipe(8) delivery agent.
Major changes - forced expiration ---------------------------------
[Feature 20200202] Support to force-expire email messages. This introduces new postsuper(1) command-line options to request expiration, and additional information in mailq(1) or postqueue(1) output.
The forced-to-expire status is stored in a queue file attribute. An expired message is returned to the sender when the queue manager attempts to deliver that message (note that Postfix will never deliver messages in the hold queue).
The postsuper(1) -e and -f options both set the forced-to-expire queue file attribute. The difference is that -f will also release a message if it is in the hold queue. With -e, such a message would not be returned to the sender until it is released with -f or -H.
In the mailq(1) or postqueue(1) -p output, a forced-to-expire message is indicated with # after the queue file name. In postqueue(1) JSON output, there is a new per-message field "forced_expire" (with value true or false) that shows the forced-to-expire status.
Major changes - haproxy2 protocol ---------------------------------
[Feature 20200112] Support for the haproxy v2 protocol. The Postfix implementation supports TCP over IPv4 and IPv6, as well as non-proxied connections; the latter are typically used for heartbeat tests.
The haproxy v2 protocol introduces no additional Postfix configuration. The Postfix smtpd(8) and postscreen(8) daemons accept both v1 and v2 protocol versions.
Major changes - logging -----------------------
[Incompat 20191109] Postfix daemon processes now log the from= and to= addresses in external (quoted) form in non-debug logging (info, warning, etc.). This means that when an address localpart contains spaces or other special characters, the localpart will be quoted, for example:
from=<"name with spaces"@example.com>
Older Postfix versions would log the internal (unquoted) form:
from=<name with spaces@example.com>
The external and internal forms are identical for the vast majority of email addresses that contain no spaces or other special characters in the localpart.
Specify "info_log_address_format = internal" for backwards compatibility.
The logging in external form is consistent with the address form that Postfix 3.2 and later prefer for table lookups. It is therefore the more useful form for non-debug logging.
Major changes - IP address normalization ----------------------------------------
[Incompat 20190427] Postfix now normalizes IP addresses received with XCLIENT, XFORWARD, or with the HaProxy protocol, for consistency with direct connections to Postfix. This may change the appearance of logging, and the way that check_client_access will match subnets of an IPv6 address. This is the Postfix 3.4 (stable) release.
The stable Postfix release is called postfix-3.4.x where 3=major release number, 4=minor release number, x=patchlevel. The stable release never changes except for patches that address bugs or emergencies. Patches change the patchlevel and the release date.
New features are developed in snapshot releases. These are called postfix-3.5-yyyymmdd where yyyymmdd is the release date (yyyy=year, mm=month, dd=day). Patches are never issued for snapshot releases; instead, a new snapshot is released.
The mail_release_date configuration parameter (format: yyyymmdd) specifies the release date of a stable release or snapshot release.
If you upgrade from Postfix 3.2 or earlier, read RELEASE_NOTES-3.3 before proceeding.
License change ---------------
This software is distributed with a dual license: in addition to the historical IBM Public License 1.0, it is now also distributed with the more recent Eclipse Public License 2.0. Recipients can choose to take the software under the license of their choice. Those who are more comfortable with the IPL can continue with that license.
Summary of changes ------------------
Incompatible changes, bdat support, containers, database support, logging, safety, tls connection pooling, tls support, usability,
Incompatible changes --------------------
[Incompat 20180826] The Postfix SMTP server announces CHUNKING (BDAT command) by default. In the unlikely case that this breaks some important remote SMTP client, disable the feature as follows:
/etc/postfix/main.cf: # The logging alternative: smtpd_discard_ehlo_keywords = chunking # The non-logging alternative: smtpd_discard_ehlo_keywords = chunking, silent_discard
See BDAT_README for more.
[Incompat 20190126] This introduces a new master.cf service 'postlog' with type 'unix-dgram' that is used by the new postlogd(8) daemon. Before backing out to an older Postfix version, edit the master.cf file and remove the postlog entry.
[Incompat 20190106] Postfix 3.4 drops support for OpenSSL 1.0.1 (end-of-life was December 31, 2016) and all earlier releases.
[Incompat 20180701] To avoid performance loss under load, the tlsproxy(8) daemon now requires a zero process limit in master.cf (this setting is provided with the default master.cf file). By default, a tlsproxy(8) process will retire after several hours.
To set the tlsproxy process limit to zero:
# postconf -F tlsproxy/unix/process_limit=0 # postfix reload
Major changes - bdat support --------------------
[Feature 20180826] Postfix SMTP server support for RFC 3030 CHUNKING (the BDAT command) without BINARYMIME, in both smtpd(8) and postscreen(8). This has no effect on Milters, smtpd_mumble_restrictions, and smtpd_proxy_filter. See BDAT_README for more.
Major changes - containers --------------------------
[Feature 20190126] Support for logging to file or stdout, instead of using syslog.
- Logging to file solves a usability problem for MacOS, and eliminates multiple problems with systemd-based systems.
- Logging to stdout is useful when Postfix runs in a container, as it eliminates a syslogd dependency.
See MAILLOG_README for configuration examples and logfile rotation.
[Feature 20180422] Better handling of undocumented(!) Linux behavior whether or not signals are delivered to a PID=1 process.
Major changes - database support --------------------------------
[Feature 20181105] Support for (key, list of filenames) in map source text.
- Currently, this feature is used only by tls_server_sni_maps.
- When a map is created from source with "postmap -F maptype:mapname", the command processes each key as usual and processes each value as a list of filenames, concatenates the content of those files (with one newline character in-between files), and stores an entry with (key, base64-encoded result).
- When a map is queried with "postmap -F -q ...", the command base64-decodes each value. It reports an error when a value is not in base64 form.
This "postmap -F -q ..." behavior also works when querying the memory-resident map types cidr:, inline:, pcre:, randmap:, regexp:, and static:. Postfix reads the files specified as table values, stores base64-encoded content, and base64-decodes content upon table lookup.
Internally, Postfix will turn on this behavior for lookups (not updates) when a map is opened with the DICT_FLAG_RHS_IS_FILE flag.
Major changes - logging -----------------------
[Feature 20190126] Support for logging to file or stdout, instead of using syslog.
- Logging to file solves a usability problem for MacOS, and eliminates multiple problems with systemd-based systems.
- Logging to stdout is useful when Postfix runs in a container, as it eliminates a syslogd dependency.
See MAILLOG_README for configuration examples and logfile rotation.
Major changes - safety ----------------------
[Feature 20180623] Automatic retirement: dnsblog(8) and tlsproxy(8) process will now voluntarily retire after after max_idle*max_use, or some sane limit if either limit is disabled. Without this, a process could stay busy for days or more.
Major changes - tls connection pooling --------------------------------------
[Feature 20180617] Postfix SMTP client support for multiple deliveries per TLS-encrypted connection. This is primarily to improve mail delivery performance for destinations that throttle clients when they don't combine deliveries.
This feature is enabled with "smtp_tls_connection_reuse=yes" in main.cf, or with "tls_connection_reuse=yes" in smtp_tls_policy_maps. It supports all Postfix TLS security levels including dane and dane-only.
The implementation of TLS connection reuse relies on the same scache(8) service as used for delivering plaintext SMTP mail, the same tlsproxy(8) daemon as used by the postscreen(8) service for inbound connections, and relies on the same hints from the qmgr(8) daemon. It reuses the configuration parameters described in CONNECTION_CACHE_README.
The Postfix SMTP client now logs whether an SMTP-over-TLS connection is newly established ("TLS connection established") or whether the connection is reused ("TLS connection reused").
The following illustrates how TLS connections are reused:
Initial plaintext SMTP handshake: smtp(8) -> remote SMTP server
Reused SMTP/TLS connection, or new SMTP/TLS connection: smtp(8) -> tlsproxy(8) -> remote SMTP server
Cached SMTP/TLS connection: scache(8) -> tlsproxy(8) -> remote SMTP server
Major changes - tls support ---------------------------
[Feature 20190106] SNI support in the Postfix SMTP server, the Postfix SMTP client, and in the tlsproxy(8) daemon (both server and client roles). See the postconf(5) documentation for the new tls_server_sni_maps and smtp_tls_servername parameters.
[Feature 20190106] Support for files that contain multiple (key, certificate, trust chain) instances. This was required to implement server-side SNI table lookups, but it also eliminates the need for separate cert/key files for RSA, DSA, Elliptic Curve, and so on. The file format is documented in the TLS_README sections "Server-side certificate and private key configuration" and "Client-side certificate and private key configuration", and in the postconf(5) documentation for the parameters smtp_tls_chain_files, smtpd_tls_chain_files, tlsproxy_client_chain_files, and tlsproxy_tls_chain_files.
Note: the command "postfix tls" does not yet support the new consolidated certificate chain format. If you switch to the new format, you'll need to manage your keys and certificates directly, rather than via postfix-tls(1).
Major changes - usability -------------------------
[Feature 20180812] Support for smtpd_reject_footer_maps (as well as the postscreen variant postscreen_reject_footer_maps) for more informative reject messages. This is indexed with the Postfix SMTP server response text, and overrides the footer specified with smtpd_reject_footer. One will want to use a pcre: or regexp: map with this.
This is the Postfix 3.3 (stable) release.
The stable Postfix release is called postfix-3.3.x where 3=major release number, 3=minor release number, x=patchlevel. The stable release never changes except for patches that address bugs or emergencies. Patches change the patchlevel and the release date.
New features are developed in snapshot releases. These are called postfix-3.4-yyyymmdd where yyyymmdd is the release date (yyyy=year, mm=month, dd=day). Patches are never issued for snapshot releases; instead, a new snapshot is released.
The mail_release_date configuration parameter (format: yyyymmdd) specifies the release date of a stable release or snapshot release.
If you upgrade from Postfix 3.1 or earlier, read RELEASE_NOTES-3.2 before proceeding.
License change ---------------
This software is distributed with a dual license: in addition to the historical IBM Public License 1.0, it is now also distributed with the more recent Eclipse Public License 2.0. Recipients can choose to take the software under the license of their choice. Those who are more comfortable with the IPL can continue with that license.
Major changes - compatibility safety net ----------------------------------------
[20180106] With compatibility_level < 1, the Postfix SMTP server now warns for mail that would be blocked by the Postfix 2.10 smtpd_relay_restrictions feature, without blocking that mail. This extends the compatibility safety net for sites that upgrade from earlier Postfix versions (questions on the postfix-users list show there is a steady trickle). See COMPATIBILITY_README for details.
Major changes - configuration -----------------------------
[20170617] The postconf command now warns about unknown parameter names in a Postfix database configuration file. As with other unknown parameter names, these warnings can help to find typos early.
[20180113] New read-only service_name parameter that contains the master.cf service name of a Postfix daemon process (it that is empty in a non-daemon process). This can make Postfix SMTP server logging logging distinct by setting the syslog_name in master.cf with "-o syslog_name=postfix/$service_name" for the "submission" and "smtps" services, and can make Postfix SMTP client distinct by setting "-o syslog_name=postfix/$service_name" for the "relay" service.
Major changes - container support ---------------------------------
[20171218] Preliminary support to run Postfix in the foreground, with "postfix start-fg". This requires that Postfix multi-instance support is disabled. To receive Postfix syslog information on the container's host, mount the host's /dev/log socket inside the container (example: "docker run -v /dev/log:/dev/log ..."), and specify a distinct Postfix "syslog_name" prefix that identifies the logging from the Postfix instance. Postfix does not log systemd events.
Major changes - database support ---------------------------------
[20170617] The postconf command warns about unknown parameter names in a Postfix database configuration file.
[20171227] The pgsql_table(5) hosts parameter now supports the postgresql:// URI syntax. Contributed by Magosányi Árpád.
Major changes - header format -----------------------------
[20180010] This release changes the format of 'full name' information in Postfix-generated From: headers, when a local program such as /bin/mail submits a message without From: header.
Postfix-generated From: headers with 'full name' information are now formatted as "From: name <address>" by default. Specify "header_from_format = obsolete" to get the earlier form "From: address (name)". See the postconf(5) manpage for more details.
Major changes - invisible changes ---------------------------------
[20170617] Additional paranoia in the VSTRING implementation: a null byte after the end of vstring buffers (this is a safety net so that C-style string operations won't scribble past the end); earlier detection of bad length and precision format string specifiers (these are the result of programming error, as Postfix format strings cannot be specified externally).
Major changes - milter support ------------------------------
[20171223] Milter applications can now send RET and ENVID parameters in SMFIR_CHGFROM (change envelope sender) requests.
Major changes - mixed IPv6/IPv4 support ---------------------------------------
[20170505] Workaround for mail delivery problems when 1) both Postfix IPv6 and IPv4 support are enabled, 2) some destination announces more primary IPv6 MX addresses than primary IPv4 MX addresses, 3) the destination is unreachable over IPv6, and 4) Postfix runs into the smtp_mx_address_limit before it can try to deliver over IPv4.
When both Postfix IPv6 and IPv4 support are enabled, the Postfix SMTP client will now relax MX preferences so that it can schedule similar numbers of IPv4 and IPv6 destination addresses. This ensures that an IPv6 connectivity problem will not prevent mail from being delivered over IPv4 (and vice versa). Specify "smtp_balance_inet_protocols = no" to disable this workaround.
Major changes - xclient -----------------------
[20171218] The Postfix SMTP server now allows the XCLIENT command before STARTTLS when TLS is required. This is useful for servers that run behind a reverse proxy server such as nginx.
This is the Postfix 3.2 (stable) release.
The stable Postfix release is called postfix-3.2.x where 3=major release number, 2=minor release number, x=patchlevel. The stable release never changes except for patches that address bugs or emergencies. Patches change the patchlevel and the release date.
New features are developed in snapshot releases. These are called postfix-3.3-yyyymmdd where yyyymmdd is the release date (yyyy=year, mm=month, dd=day). Patches are never issued for snapshot releases; instead, a new snapshot is released.
The mail_release_date configuration parameter (format: yyyymmdd) specifies the release date of a stable release or snapshot release.
If you upgrade from Postfix 3.0 or earlier, read RELEASE_NOTES-3.1 before proceeding.
Invisible changes -----------------
In addition to the visible changes described below, there is an ongoing overhaul of low-level code. With each change come updated tests to ensure that future changes will not 'break' compatibility with past behavior.
Major changes - address mapping -------------------------------
[Feature 20170128] Postfix 3.2 fixes the handling of address extensions with email addresses that contain spaces. For example, the virtual_alias_maps, canonical_maps, and smtp_generic_maps features now correctly propagate an address extension from "aa bb+ext"@example.com to "cc dd+ext"@other.example, instead of producing broken output.
Major changes - header/body_checks ----------------------------------
[Feature 20161008] "PASS" and "STRIP" actions in header/body_checks. "STRIP" is similar to "IGNORE" but also logs the action, and "PASS" disables header, body, and Milter inspection for the remainder of the message content. Contributed by Hobbit.
Major changes - log analysis ----------------------------
[Feature 20160330] The collate.pl script by Viktor Dukhovni for grouping Postfix logfile records into "sessions" based on queue ID and process ID information. It's in the auxiliary/collate directory of the Postfix source tree.
Major changes - maps support ----------------------------
[Feature 20160527] Postfix 3.2 cidr tables support if/endif and negation (by prepending ! to a pattern), just like regexp and pcre tables. The primarily purpose is to improve readability of complex tables. See the cidr_table(5) manpage for syntax details.
[Incompat 20160925] In the Postfix MySQL database client, the default option_group value has changed to "client", to enable reading of "client" option group settings in the MySQL options file. This fixes a "not found" problem with Postfix queries that contain UTF8-encoded non-ASCII text. Specify an empty option_group value (option_group =) to get backwards-compatible behavior.
[Feature 20161217] Stored-procedure support for MySQL databases. Contributed by John Fawcett. See mysql_table(5) for instructions.
[Feature 20170128] The postmap command, and the inline: and texthash: maps now support spaces in left-hand field of the lookup table "source text". Use double quotes (") around a left-hand field that contains spaces, and use backslash (\) to protect embedded quotes in a left-hand field. There is no change in the processing of the right-hand field.
Major changes - milter support ------------------------------
[Feature 20160611] The Postfix SMTP server local IP address and port are available in the policy delegation protocol (attribute names: server_address, server_port), in the Milter protocol (macro names: {daemon_addr}, {daemon_port}), and in the XCLIENT protocol (attribute names: DESTADDR, DESTPORT).
[Feature 20161024] smtpd_milter_maps support for per-client Milter configuration that overrides smtpd_milters, and that has the same syntax. A lookup result of "DISABLE" turns off Milter support. See MILTER_README.html for details.
Major changes - policy delegation ---------------------------------
[Feature 20160611] The Postfix SMTP server local IP address and port are available in the policy delegation protocol (attribute names: server_address, server_port), in the Milter protocol (macro names: {daemon_addr}, {daemon_port}), and in the XCLIENT protocol (attribute names: DESTADDR, DESTPORT).
Major changes - postqueue -------------------------
[Incompat 20170129] The postqueue command no longer forces all message arrival times to be reported in UTC. To get the old behavior, set TZ=UTC in main.cf:import_environment (this override is not recommended, as it affects all Postfix utities and daemons).
Major changes - safety ----------------------
[Incompat 20161227] For safety reasons, the sendmail -C option must specify an authorized directory: the default configuration directory, a directory that is listed in the default main.cf file with alternate_config_directories or multi_instance_directories, or the command must be invoked with root privileges (UID 0 and EUID 0). This mitigates a recurring problem with the PHP mail() function.
Major changes - sasl --------------------
[Feature 20160625] The Postfix SMTP server now passes remote client and local server network address and port information to the Cyrus SASL library. Build with ``make makefiles "CCARGS=$CCARGS -DNO_IP_CYRUS_SASL_AUTH"'' for backwards compatibility.
Major changes - smtputf8 ------------------------
[Feature 20161103] Postfix 3.2 disables the 'transitional' compatibility between the IDNA2003 and IDNA2008 standards for internationalized domain names (domain names beyond the limits of US-ASCII).
This change makes Postfix behavior consistent with contemporary web browsers. It affects the handling of some corner cases such as German sz and Greek zeta. See http://unicode.org/cldr/utility/idna.jsp for more examples.
Specify "enable_idna2003_compatibility = yes" to restore historical behavior (but keep in mind that the rest of the world may not make that same choice).
Major changes - tls -------------------
[Feature 20160828] Fixes for deprecated OpenSSL 1.1.0 API features, so that Postfix will build without depending on backwards-compatibility support.
[Incompat 20161204] Postfix 3.2 removes tentative features that were implemented before the DANE spec was finalized:
- Support for certificate usage PKIX-EE(1),
- The ability to disable digest agility (Postfix now behaves as if "tls_dane_digest_agility = on"), and
- The ability to disable support for "TLSA 2 [01] [12]" records that specify the digest of a trust anchor (Postfix now behaves as if "tls_dane_trust_anchor_digest_enable = yes).
[Feature 20161217] Postfix 3.2 enables elliptic curve negotiation with OpenSSL >= 1.0.2. This changes the default smtpd_tls_eecdh_grade setting to "auto", and introduces a new parameter tls_eecdh_auto_curves with the names of curves that may be negotiated.
The default tls_eecdh_auto_curves setting is determined at compile time, and depends on the Postfix and OpenSSL versions. At runtime, Postfix will skip curve names that aren't supported by the OpenSSL library.
Major changes - xclient -----------------------
[Feature 20160611] The Postfix SMTP server local IP address and port are available in the policy delegation protocol (attribute names: server_address, server_port), in the Milter protocol (macro names: {daemon_addr}, {daemon_port}), and in the XCLIENT protocol (attribute names: DESTADDR, DESTPORT).
show more ...
|
#
837e7c1a |
| 14-Feb-2017 |
christos <christos@NetBSD.org> |
The stable Postfix release is called postfix-3.0.x where 3=major release number, 0=minor release number, x=patchlevel. The stable release never changes except for patches that address bugs or emerge
The stable Postfix release is called postfix-3.0.x where 3=major release number, 0=minor release number, x=patchlevel. The stable release never changes except for patches that address bugs or emergencies. Patches change the patchlevel and the release date.
New features are developed in snapshot releases. These are called postfix-3.1-yyyymmdd where yyyymmdd is the release date (yyyy=year, mm=month, dd=day). Patches are never issued for snapshot releases; instead, a new snapshot is released.
The mail_release_date configuration parameter (format: yyyymmdd) specifies the release date of a stable release or snapshot release.
If you upgrade from Postfix 2.10 or earlier, read RELEASE_NOTES-2.11 before proceeding.
Notes for distribution maintainers ----------------------------------
* New backwards-compatibility safety net.
With NEW Postfix installs, you MUST install a main.cf file with the setting "compatibility_level = 2". See conf/main.cf for an example.
With UPGRADES of existing Postfix systems, you MUST NOT change the main.cf compatibility_level setting, nor add this setting if it does not exist.
Several Postfix default settings have changed with Postfix 3.0. To avoid massive frustration with existing Postfix installations, Postfix 3.0 comes with a safety net that forces Postfix to keep running with backwards-compatible main.cf and master.cf default settings. This safety net depends on the main.cf compatibility_level setting (default: 0). Details are in COMPATIBILITY_README.
* New Postfix build system.
The Postfix build/install procedure has changed to support Postfix dynamically-linked libraries and database plugins. These must not be "shared" with non-Postfix programs, and therefore must not be installed in a public directory.
To avoid massive frustration due to broken patches, PLEASE BUILD POSTFIX FIRST WITHOUT APPLYING ANY PATCHES. Follow the INSTALL instructions (see "Building with Postfix dynamically-linked libraries and database plugins"), and see how things work and what the dynamically-linked libraries, database plugin, and configuration files look like. Then, go ahead and perform your platform-specific customizations. The INSTALL section "Tips for distribution maintainers" has further suggestions.
Major changes - critical ------------------------
[Incompat 20140714] After upgrading Postfix, "postfix reload" (or start/stop) is required. Several Postfix-internal protocols have been extended to support SMTPUTF8. Failure to reload or restart will result in mail staying queued, while Postfix daemons log warning messages about unexpected attributes.
Major changes - default settings --------------------------------
[Incompat 20141009] The default settings have changed for relay_domains (new: empty, old: $mydestination) and mynetworks_style (new: host, old: subnet). However the backwards-compatibility safety net will prevent these changes from taking effect, giving the system administrator the option to make an old default setting permanent in main.cf or to adopt the new default setting, before turning off backwards compatibility. See COMPATIBILITY_README for details.
[Incompat 20141001] A new backwards-compatibility safety net forces Postfix to run with backwards-compatible main.cf and master.cf default settings after an upgrade to a newer but incompatible Postfix version. See COMPATIBILITY_README for details.
While the backwards-compatible default settings are in effect, Postfix logs what services or what email would be affected by the incompatible change. Based on this the administrator can make some backwards-compatibility settings permanent in main.cf or master.cf, before turning off backwards compatibility.
See postconf.5.html#compatibility_level for details.
[Incompat 20141001] The default settings have changed for append_dot_mydomain (new: no. old: yes), master.cf chroot (new: n, old: y), and smtputf8 (new: yes, old: no).
Major changes - access control ------------------------------
[Feature 20141119] Support for BCC actions in header/body_checks and milter_header_checks. There is no limit on the number of BCC actions that may be specified, other than the implicit limit due to finite storage. BCC support will not be implemented in Postfix delivery agent header/body_checks.
It works in the same way as always_bcc and sender/recipient_bcc_maps: there can be only one address per action, recipients are added with the NOTIFY=NONE delivery status notification option, and duplicate recipients are ignored (with the same delivery status notification options).
[Incompat 20141009] The default settings have changed for relay_domains (new: empty, old: $mydestination) and mynetworks_style (new: host, old: subnet). However the backwards-compatibility safety net will prevent these changes from taking effect, giving the system administrator the option to make an old default setting permanent in main.cf or to adopt the new default setting, before turning off backwards compatibility. See COMPATIBILITY_README for details.
[Feature 20140618] New INFO action in access(5) tables, for consistency with header/body_checks.
[Feature 20140620] New check_xxx_a_access (for xxx in client, reverse_client, helo, sender, recipient) implements access control on all A and AAAA IP addresses for respectively the client hostname, helo parameter, sender domain or recipient domain. This complements the existing check_xxx_mx_access and check_xxx_ns_access features.
Major changes - address rewriting ---------------------------------
[Incompat 20141001] The default settings have changed for append_dot_mydomain (new: no. old: yes), master.cf chroot (new: n, old: y), and smtputf8 (new: yes, old: no).
Major changes - address verification ------------------------------------
[Feature 20141227] The new smtp_address_verify_target parameter (default: rcpt) specifies what protocol stage decides if a recipient is valid. Specify "data" for servers that reject invalid recipients in response to the DATA command.
Major changes - database support --------------------------------
[Feature 20140512] Support for Berkeley DB version 6.
[Feature 20140618] The "randmap" lookup table performs random selection. This may be used to implement load balancing, for example:
/etc/postfix/transport: # Deliver my own domain as usual. example.com : .example.com :
/etc/postfix/main.cf: transport_maps = # Deliver my own domain as usual. hash:/etc/postfix/transport # Deliver other domains via randomly-selected relayhosts randmap:{smtp:smtp0.example.com, smtp:smtp1.example.com}
A variant of this can randomly select SMTP clients with different smtp_bind_address settings.
To implement different weights, specify lookup results multiple times. For example, to choose smtp:smtp1.example.com twice as often as smtp:smtp0.example.com, specify smtp:smtp1.example.com twice.
A future version may support randmap:/path/to/file to load a list of results from file.
[Feature 20140618] As the name suggests, the "pipemap" table implements a pipeline of lookup tables. The name of the table specifies the pipeline as a sequence of tables. For example, the following prevents SMTP mail to system accounts that have "nologin" as their login shell:
/etc/postfix/main.cf: local_recipient_maps = pipemap:{unix:passwd.byname, pcre:/etc/postfix/no-nologin.pcre} alias_maps
/etc/postfix/no-nologin.pcre: !/nologin/ whatever
Each "pipemap:" query is given to the first table. Each table lookup result becomes the query for the next table in the pipeline, and the last table produces the final result. When any table lookup produces no result, the entire pipeline produces no result.
A future version may support pipemap:/path/to/file to load a list of lookup tables from file.
[Feature 20140924] Support for unionmap, with the same syntax as pipemap. This sends a query to all tables, and concatenates non-empty results, separated by comma.
[Feature 20131121] The "static" lookup table now supports whitespace when invoked as "static:{ text with whitespace }", so that it can be used, for example, at the end of smtpd_mumble_restrictions as "check_mumble_access static:{reject text...}".
[Feature 20141126] "inline:{key=value, { key = text with comma/space}}" avoids the need to create a database for just a few entries.
Major changes - delivery status notifications ---------------------------------------------
[Feature 20140321] Delivery status filter support, to replace the delivery status codes and explanatory text of successful or unsuccessful deliveries by Postfix mail delivery agents.
This was originally implemented for sites that want to turn certain soft delivery errors into hard delivery errors, but it can also be used to censor out information from delivery confirmation reports.
This feature is implemented as a filter that replaces the three-number enhanced status code and descriptive text in Postfix delivery agent success, bounce, or defer messages. Note: this will not override "soft_bounce=yes", and this will not change a successful delivery status into an unsuccessful status or vice versa.
The first example turns specific soft TLS errors into hard errors, by overriding the first number in the enhanced status code.
/etc/postfix/main.cf: smtp_delivery_status_filter = pcre:/etc/postfix/smtp_dsn_filter
/etc/postfix/smtp_dsn_filter: /^4(\.\d+\.\d+ TLS is required, but host \S+ refused to start TLS: .+)/ 5$1 /^4(\.\d+\.\d+ TLS is required, but was not offered by host .+)/ 5$1
The second example removes the destination command name and file name from local(8) successful delivery reports, so that they will not be reported when a sender requests confirmation of delivery.
/etc/postfix/main.cf: local_delivery_status_filter = pcre:/etc/postfix/local_dsn_filter
/etc/postfix/local_dsn_filter: /^(2\S+ delivered to file).+/ $1 /^(2\S+ delivered to command).+/ $1
This feature is supported in the lmtp(8), local(8), pipe(8), smtp(8) and virtual(8) delivery agents. That is, all delivery agents that actually deliver mail. It will not be implemented in the error and retry pseudo-delivery agents.
The new main.cf parameters and default values are:
default_delivery_status_filter = lmtp_delivery_status_filter = $default_delivery_status_filter local_delivery_status_filter = $default_delivery_status_filter pipe_delivery_status_filter = $default_delivery_status_filter smtp_delivery_status_filter = $default_delivery_status_filter virtual_delivery_status_filter = $default_delivery_status_filter
See the postconf(5) manpage for more details.
[Incompat 20140618] The pipe(8) delivery agent will now log a limited amount of command output upon successful delivery, and will report that output in "SUCCESS" delivery status reports. This is another good reason to disable inbound DSN requests at the Internet perimeter.
[Feature 20140907] With "confirm_delay_cleared = yes", Postfix informs the sender when delayed mail leaves the queue (this is in addition to the delay_warning_time feature that warns when mail is still queued). This feature is disabled by default, because it can result in a sudden burst of notifications when the queue drains at the end of a prolonged network outage.
Major changes - dns -------------------
[Feature 20141128] Support for DNS server reply filters in the Postfix SMTP/LMTP client and SMTP server. This helps to work around mail delivery problems with sites that have incorrect DNS information. Note: this has no effect on the implicit DNS lookups that are made by nsswitch.conf or equivalent mechanisms.
This feature renders each lookup result as one line of text in standard zone-file format as shown below. The class field is always "IN", the preference field exists only for MX records, the names of hosts, domains, etc. end in ".", and those names are in ASCII form (xn--mumble form for internationalized domain names).
name ttl class type preference value --------------------------------------------------------- postfix.org. 86400 IN MX 10 mail.cloud9.net.
Typically, one would match this text with a regexp: or pcre: table. When a match is found, the table lookup result specifies an action. By default, the table query and the action name are case-insensitive. Currently, only the IGNORE action is implemented.
For safety reasons, Postfix logs a warning or defers mail delivery when a DNS reply filter removes all lookup results from a successful query.
The Postfix SMTP/LMTP client uses the smtp_dns_reply_filter and lmtp_dns_reply_filter features only for Postfix SMTP client lookups of MX, A, and AAAAA records to locate a remote SMTP or LMTP server, including lookups that implement the features reject_unverified_sender and reject_unverified_recipient. The filters are not used for lookups made through nsswitch.conf and similar mechanisms.
The Postfix SMTP server uses the smtpd_dns_reply_filter feature only for Postfix SMTP server lookups of MX, A, AAAAA, and TXT records to implement the features reject_unknown_helo_hostname, reject_unknown_sender_domain, reject_unknown_recipient_domain, reject_rbl_*, and reject_rhsbl_*. The filter is not used for lookups made through nsswitch.conf and similar mechanisms, such as lookups of the remote SMTP client name.
[Feature 20141126] Nullmx support (MX records with a null hostname). This change affects error messages only. The Postfix SMTP client already bounced mail for such domains, and the Postfix SMTP server already rejected such domains with reject_unknown_sender/recipient_domain. This feature introduces a new SMTP server configuration parameter nullmx_reject_code (default: 556).
Major changes - dynamic linking -------------------------------
[Feature 20140530] Support to build Postfix with Postfix dynamically-linked libraries, and with dynamically-loadable database clients. These MUST NOT be used by non-Postfix programs. Postfix dynamically-linked libraries introduce minor runtime overhead and result in smaller Postfix executable files. Dynamically-loadable database clients are useful when you distribute or install pre-compiled packages. Postfix 3.0 supports dynamic loading for CDB, LDAP, LMDB, MYSQL, PCRE, PGSQL, SDBM, and SQLITE database clients.
This implementation is based on Debian code by LaMont Jones, initially ported by Viktor Dukhovni. Currently, support exists for recent versions of Linux, FreeBSD, MacOS X, and for the ancient Solaris 9.
To support Postfix dynamically-linked libraries and dynamically-loadable database clients, the Postfix build procedure had to be changed (specifically, the files makedefs and Makefile.in, and the files postfix-install and post-install that install or update Postfix).
[Incompat 20140530] The Postfix 3.0 build procedure expects that you specify database library dependencies with variables named AUXLIBS_CDB, AUXLIBS_LDAP, etc. With Postfix 3.0 and later, the old AUXLIBS variable still supports building a statically-loaded CDB etc. database client, but only the new AUXLIBS_CDB etc. variables support building a dynamically-loaded or statically-loaded CDB etc. database client. See CDB_README, LDAP_README, etc. for details.
Failure to follow this advice will defeat the purpose of dynamic database client loading. Every Postfix executable file will have database library dependencies. And that was exactly what dynamic database client loading was meant to avoid.
Major changes - future proofing -------------------------------
[Cleanup 20141224] The changes described here have no visible effect on Postfix behavior, but they make Postfix code easier to maintain, and therefore make new functionality easier to add.
* Compile-time argument typechecks of non-printf/scanf-like variadic function argument lists.
* Deprecating the use of "char *" for non-text purposes such as memory allocation and pointers to application context for call-back functions. This dates from long-past days before void * became universally available.
* Replace integer types for counters and sizes with size_t or ssize_t equivalents. This eliminates some wasteful 64<->32bit conversions on 64-bit systems.
Major changes - installation pathnames --------------------------------------
[Incompat 20140625] For compliance with file system policies, some non-executable files have been moved from $daemon_directory to the directory specified with the new meta_directory configuration parameter which has the same default value as the config_directory parameter. This change affects non-executable files that are shared between multiple Postfix instances such as postfix-files, dynamicmaps.cf, and multi-instance template files.
For backwards compatibility with Postfix 2.6 .. 2.11, specify "meta_directory = $daemon_directory" in main.cf before installing or upgrading Postfix, or specify "meta_directory = /path/name" on the "make makefiles", "make install" or "make upgrade" command line.
Major changes - milter ----------------------
[Feature 20140928] Support for per-Milter settings that override main.cf parameters. For details see the section "Advanced policy client configuration" in the SMTPD_POLICY_README document.
Here is an example that uses both old and new syntax:
smtpd_milters = { inet:127.0.0.1:port1, default_action=accept, ... }, inet:127.0.0.1:port2, ...
The supported attribute names are: command_timeout, connect_timeout, content_timeout, default_action, and protocol. These have the same names as the corresponding main.cf parameters, without the "milter_" prefix.
The per-milter settings are specified as attribute=value pairs separated by comma or space; specify { name = value } to allow spaces around the "=" or within an attribute value.
[Feature 20141018] DMARC compatibility: when a Milter inserts a header ABOVE Postfix's own Received: header, Postfix no longer exposes its own Received: header to Milters (violating protocol) and Postfix no longer hides the Milter-inserted header from Milters (wtf).
Major changes - parameter syntax --------------------------------
[Feature 20140921] In preparation for configurable mail headers and logging, new main.cf support for if-then-else expressions:
${name?{text1}:{text2}}
and for logical expressions:
${{text1}=={text2}?{text3}:{text4}} ${{text1}!={text2}?{text3}:{text4}}
Whitespace before and after {text} is ignored. This can help to make complex expressions more readable. See the postconf(5) manpage for further details.
[Feature 20140928] Support for whitespace in daemon command-line arguments. For details, see the "Command name + arguments" section in the master(5) manpage. Example:
smtpd -o { parameter = value containing whitespace } ...
The { ... } form is also available for non-option command-line arguments in master.cf, for example:
pipe ... argv=command { argument containing whitespace } ...
In both cases, whitespace immediately after "{" and before "}" is ignored.
[Feature 20141005] Postfix import_environment and export_environment now allow "{ name=value }" to protect whitespace in attribute values.
[Feature 20141006] The new message_drop_header parameter replaces a hard-coded table that specifies what message headers the cleanup daemon will remove. The list of supported header names covers RFC 5321, 5322, MIME RFCs, and some historical names.
Major changes - pipe daemon ---------------------------
[Incompat 20140618] The pipe(8) delivery agent will now log a limited amount of command output upon successful delivery, and will report that output in "SUCCESS" delivery status reports. This is another good reason to disable inbound DSN requests at the Internet perimeter.
Major changes - policy client -----------------------------
[Feature 20140703] This release introduces three new configuration parameters that control error recovery for failed SMTPD policy requests.
* smtpd_policy_service_default_action (default: 451 4.3.5 Server configuration problem): The default action when an SMTPD policy service request fails.
* smtpd_policy_service_try_limit (default: 2): The maximal number of attempts to send an SMTPD policy service request before giving up. This must be a number greater than zero.
* smtpd_policy_service_retry_delay (default: 1s): The delay between attempts to resend a failed SMTPD policy service request. This must be a number greater than zero.
See postconf(5) for details and limitations.
[Feature 20140928] Support for per-policy service settings that override main.cf parameters. For details see the section "Different settings for different Milter applications" in the MILTER_README document.
Here is an example that uses both old and new syntax:
smtpd_recipient_restrictions = ... check_policy_service { inet:127.0.0.1:port3, default_action=DUNNO } check_policy_service inet:127.0.0.1:port4 ...
The per-policy service settings are specified as attribute=value pairs separated by comma or space; specify { name = value } to allow spaces around the "=" or within an attribute value.
The supported attribute names are: default_action, max_idle, max_ttl, request_limit, retry_delay, timeout, try_limit. These have the same names as the corresponding main.cf parameters, without the "smtpd_policy_service_" prefix.
[Feature 20140505] A client port attribute was added to the policy delegation protocol.
[Feature 20140630] New smtpd_policy_service_request_limit feature to limit the number of requests per Postfix SMTP server policy connection. This is a workaround to avoid error-recovery delays with policy servers that cannot maintain a persistent connection.
Major changes - position-independent executables ------------------------------------------------
[Feature 20150205] Preliminary support for building position-independent executables (PIE), tested on Fedora Core 20, Ubuntu 14.04, FreeBSD 9 and 10, and NetBSD 6. Specify:
$ make makefiles pie=yes ...other arguments...
On some systems, PIE is used by the ASLR exploit mitigation technique (ASLR = Address-Space Layout Randomization). Whether specifying "pie=yes" has any effect at all depends on the compiler. Reportedly, some compilers always produce PIE executables.
Major changes - postscreen --------------------------
[Feature 20140501] Configurable time limit (postscreen_dnsbl_timeout) for DNSBL or DNSWL lookups. This is separate from the timeouts in the dnsblog(8) daemon which are controlled by system resolver(3) routines.
Major changes - session fingerprint -----------------------------------
[Feature 20140801] The Postfix SMTP server now logs at the end of a session how many times an SMTP command was successfully invoked, followed by the total number of invocations if some invocations were unsuccessful.
This logging will enough to diagnose many problems without using verbose logging or network sniffer.
Normal session, no TLS: disconnect from name[addr] ehlo=1 mail=1 rcpt=1 data=1 quit=1
Normal session. with TLS: disconnect from name[addr] ehlo=2 starttls=1 mail=1 rcpt=1 data=1 quit=1
All recipients rejected, no ESMTP command pipelining: disconnect from name[addr] ehlo=1 mail=1 rcpt=0/1 quit=1
All recipients rejected, with ESMTP command pipelining: disconnect from name[addr] ehlo=1 mail=1 rcpt=0/1 data=0/1 rset=1 quit=1
Password guessing bot, hangs up without QUIT: disconnect from name[addr] ehlo=1 auth=0/1
Mis-configured client trying to use TLS wrappermode on port 587: disconnect from name[addr] unknown=0/1
Logfile analyzers can trigger on the presence of "/". It indicates that Postfix rejected at least one command.
[Feature 20150118] As a late addition, the SMTP server now also logs the total number of commands (as "commands=x/y") even when the client did not send any commands. This helps logfile analyzers to recognize sessions without commands.
Major changes - smtp client ---------------------------
[Feature 20141227] The new smtp_address_verify_target parameter (default: rcpt) determines what protocol stage decides if a recipient is valid. Specify "data" for servers that reject recipients after the DATA command.
Major changes - smtputf8 ------------------------
[Incompat 20141001] The default settings have changed for append_dot_mydomain (new: no, old: yes), master.cf chroot (new: n, old: y), and smtputf8 (new: yes, old: no).
[Incompat 20140714] After upgrading Postfix, "postfix reload" (or start/stop) is required. Several Postfix-internal protocols have been extended to support SMTPUTF8. Failure to reload or restart will result in mail staying queued, while Postfix daemons log warning messages about unexpected attributes.
[Feature 20140715] Support for Email Address Internationalization (EAI) as defined in RFC 6531..6533. This supports UTF-8 in SMTP/LMTP sender addresses, recipient addresses, and message header values. The implementation is based on initial work by Arnt Gulbrandsen that was funded by CNNIC.
See SMTPUTF8_README for a description of Postfix SMTPUTF8 support.
[Feature 20150112] UTF-8 Casefolding support for Postfix lookup tables and matchlists (mydestination, relay_domains, etc.). This is enabled only with "smtpuf8 = yes".
[Feature 20150112] With smtputf8_enable=yes, SMTP commands with UTF-8 syntax errors are rejected, table lookup results with invalid UTF-8 syntax are handled as configuration errors, and UTF-8 syntax errors in policy server replies result in execution of the policy server's default action.
Major changes - tls support ---------------------------
(see "Major changes - delivery status notifications" above for turning 4XX soft errors into 5XX bounces when a remote SMTP server does not offer STARTTLS support).
[Feature 20140209] the Postfix SMTP client now also falls back to plaintext when TLS fails AFTER the TLS protocol handshake.
[Feature 20140218] The Postfix SMTP client now requires that a queue file is older than $minimal_backoff_time, before falling back from failed TLS to plaintext (both during or after the TLS handshake).
[Feature 20141021] Per IETF TLS WG consensus, the tls_session_ticket_cipher default setting was changed from aes-128-cbc to aes-256-cbc.
[Feature 20150116] TLS wrappermode support in the Postfix smtp(8) client (new smtp_tls_wrappermode parameter) and in posttls-finger(1) (new -w option). There still is life in that deprecated protocol, and people should not have to jump hoops with stunnel.
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