=======================
 GNU Mailman 3 changes
=======================

Copyright (C) 1998-2018 by the Free Software Foundation, Inc.
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA

Here is a history of user visible changes to Mailman.


3.3.1
=====

(2020-04-19)

Bugs
----
* Allow ``action`` for header matches to be None in REST interface. (Closes #671)
* It is now possible to add the list posting address with nonmember role, e.g.
  to give it a moderaction of discard.  (Closes #633)
* The issue of posting a message without a To: header to a fully personalized
  list throwing a KeyError has been fixed.  (Closes #639)
* Confirmation or moderator approval of a subscription from an address banned
  subsequent to subscribing will no longer succeed.  (Closes #642)
* Fixed an issue caused by the fix for #642 where email confirmation of a
  banned subscription address would cause a shunted message.  (Closes #643)
* Fixed a bug where the ``postfix_vmap`` file would merge two columns for long
  domain names. (Closes #651)
* Fix failing test cases due to changed API in a new version of dkimpy. (Closes
  #655)
* Mailman now auto-geneartes alias maps when it starts for the first
  time. (Closes #469)
* Sending a bounce probe now resets ``bounce_score``.  (Closes #660)
* Bounce probes which bounce are now properly recognized.  (Closes #661)
* Residual bounces are logged but are not processed further.  (Closes #662)
* Disabling delivery by bounce properly initializes some bounce info so
  warnings can be sent and the member eventually removed.  (Closes #663)
* Bouncing member is not removed until
  ``bounce_you_are_disabled_warnings_interval`` after the last warning was
  sent.  (Closes #664)
* Fixed recipient address in delivery disabled by bounce notice to the user.
  (Closes #665)
* Residial bounces are now marked as processed.  (Closes #669)
* Find members API now searches for the Member's display name too. (Closes #667)
* Content filtering ``convert_html_to_plaintext`` no longer creates messages
  that can't be flattened as_bytes.  (Closes #677)
* Removed an incorrect failing assertion when confirming a confirm_then_moderate
  unsubscription.  (Closes #553)
* Fix a bug due to incompatible API of a new version of ``importlib_resources``
  library which causes Templates loading to fail. (Closes #691)
* Fix a bug due to incompatible API of a new version of ``zope.intefaces``.
  (See !606)
* Import21 no longer tries to import banned addresses.  (Closes #688)

Command line
------------
* A new ``mailman members --sync`` command has been added to help you
synchronize subscribed mailing list members against a text list of
subscription addresses. (see !545)

REST
----
* Expose ``max_days_to_hold``, ``accept_these_nonmembers``,
  ``reject_these_nonmembers``, ``discard_these_nonmembers``,
  ``hold_these_nonmembers``, ``personalize``, and ``unsubscription_policy``
  attributes of a MailingList through API. (See !570)
* Add a new ``send_welcome_message`` flag when subscribing users to override
  MailingList's default setting. (Closes #362)
* Expose content filtering settings for MailingList. (Closes #694)
* Add ``advertised`` attribute to ``MailingList`` object so Postorius doesn't
  have to make multiple calls for Index Page. (See !608)
* Expose ``filter_action`` attribute of MailingList through API. (See !609)

Features
--------
* Add support for processing of email bounce events. Thanks to Aaryan Bhagat for
  working on this as a part of his GSoC project and Thanks to Google for
  sponsoring the project as a part of GSoC.(See !584)


3.3.0 -- "Tom Sawyer"
=====================
(2019-09-04)

Bugs
----
* A list member with ``receive_list_copy`` set to ``False`` who is addressed in
  ``CC`` will now be removed from ``CC`` even if this results in no ``CC``.
  (Closes #575)
* ``X-Mailman-Approved-At`` header now has correct timezone.  (Closes #584)
* A spurious ``invalid FilterAction: discard. Treating as discard`` log
  message is eliminated.  (Closes #592)
* A post from a nonmember matching the legacy ``accept_these_nonmembers`` is
  now subject to subsequent rules rather than accepted immediately.
  (Closes #587)
* Email attempts to subscribe a user who is banned or has a subscription
  already pending are now handled properly.  (Closes #577 and #583)
* It is no longer possible to add the list's posting address with any role to
  a list.  (Closes #599)
* Fixed the nntp runner which was calling the ``nntplib.NNTP.post()`` method
  with a string object instead of bytes.  (Closes #613)
* A post with a Reply-To: the list address will no longer be shunted.
  (Closes #614)
* Encoded (base64 or quoted-printable) HTML message bodies are now decoded for
  ``html_to_plaintext``.  (Closes #616)
* Non-VERPed temporary failure DSNs are no longer reported as unrecognized
  bounces.  (Closes #622)
* Fix ``mailman import21`` command to work in Python 3.7.4 and Python 3.8b4
  (Closes #625)

Command line
------------
* The ``mailman import21`` command now leaves only regexps in the legacy
  ``*_these_nonmembers`` list attributes.  (Closes #588)
* The ``mailman import21`` command now imports nonmember accept actions as
  ``Action.defer`` rather than ``Action.accept``.  (Closes #579)
* The ``mailman import21`` command now correctly imports ``*_these_nonmembers``
  actions for nonmembers following a member in the list.  (Closes #580)
* The progress meter while ``mailman import21`` is importing rosters has been
  shortened so it no longer wraps and scrolls.  (Closes #589)
* The ``mailman import21`` command no longer sends an email to existing owners
  for each imported member.  (Closes #605)
* A ``mailman notify`` command has been implemented to be run by cron to send
  periodic notices of held requests to list owners and moderators.
  (Closes #258)
* The ``mailman import21`` command now imports ``private_roster``.
  (Closes #607)
* A ``mailman gatenews`` command has been implemented to be run by cron to gate
  messages from usenet to those lists which have the gateway configured.
* The ``mailman members --add`` command no longer prints a stack trace if an
  invalid email address is given.  (See !544)
* A new ``mailman members --remove`` command has been added to help you
  mass-unsubscribe subscribers from a mailing list.

REST
----
* Expose a user's preferred address using REST API. (Closes #240)
* Expose `header_matches/find` API to find a list of ``HeaderMatches`` belonging
  to a MailingList. (See !497)
* Allow adding a comment when rejecting held messages. (Closes #594)
* Fix a 500 error when creating a user with invalid email address. (Closes #263)

Localization
------------
* Add French translations for mail templates. (See !522)

Other
-----
* Add a new attribute ``tag`` to ``HeaderMatch`` to find and manage a set of
  rules. (See !497)
* Expired cached entries will be deleted efficiently. (Closes #462)
* REST Runner now uses Gunicorn to run WSGI server instead of the standard
  library wsgiref for better performance.
* Add support for SMPTS/STARTTLS for connections to MTA. (See !508)
* The last remnants of the mailing list attribute ``nntp_host`` have been
  removed.  (Closes #611)
* Email confirmation requests now include an ``Auto-Submitted`` header to
  prevent robotic replies per ``RFC 3834``.  (Closes #23)
* The mail->news gateway no longer munges Message-ID headers unless the
  original Message-ID is rejected by the ``nntp_host``.  (Closes #24)

3.2.2
=====
(2019-03-23)

REST
----
* Failed validation to new Mailing List creation and Domain creation no longer
  returns 500 errors.
* Expose ``preferred_language`` for MailingList through REST API.
* Self-link of banned emails will be url-encoded when the email is actually
  a regex, mainly to prevent misplaced `?` in the link.
* REST API now accepts inputs in JSON format. (See !451)
* REST API errors are now always formatted as JSON. (See !451)
* Failed request validations now return more verbose errors, like ``Enum`` types
  return all acceptable values. (See !451)
* REST API accepts request with content type None (See !479)


Command line
------------
* The ``mailman import21`` command now displays import progress.  (Closes #561)
* An issue with ``mailman subcommand --help`` hanging has been worked around.
  (Closes #520)


3.2.1
=====
(2019-02-22)

Command line
------------
* The ``mailman import21`` command properly converts all acceptable_aliases
  to regexps.  (Closes #496)
* The ``mailman import21`` command correctly converts autorespond_* settings.
  (Closes #505)
* The various ``mailman`` commands now issue a help hint in case of error.
  Tests have been updated to recognize this.  (Closes #519)

Bugs
----
* Open non-regular log files (e.g. fifos) in write mode instead of append mode.
  (See !407)
* Autoresponses to posts and -owner and -request messages now work.
  (Closes #504)
* Message parts are now properly decoded when trying to remove an Approved:
  header.  (Closes #518)
* Outgoing SMTP connections are now closed following message delivery
  regardless of the max_sessions_per_connection setting.  (Closes #529)
* Messages with Subject: Re: only are now processed correctly.  (Closes #545)

LOCALIZATION
------------
* Added German translations for mail templates. Thanks to the "Institut für
  Gebrauchsgrafik" for providing them. (Closes #534)

REST
----
* Allow setting ``max_num_recipients`` for a mailing list.  (Closes #508)
* Add a per-list visibility option for Members. (Closes #108)

Other
-----
* Email commands are now case insensitive.  (Closes #353)
* Implicit commands sent to -join, -leave and -confirm addresses no longer
  generate a Results email.  (Closes #516)
* An ``explicit_header_only`` option has been added to Reply-To: munging to
  avoid putting the list address in Cc:.  (Closes #531)
* The default list welcome message has been cleaned up a bit.  (Closes #530)
* A substitution variable ``user_name_or_email`` has been added to
  ``list:member:regular:header`` and ``list:member:regular:footer`` templates
  when personalized deliveries are enabled.  (Closes #533)
* The template search algorithm was fixed to look for in-tree templates for
  each language in the search list. (Closes #535)
* Set default subscription policy to "confirm then moderate" for private
  mailing list style. (Closes #536)


3.2.0 -- "La Villa Strangiato"
==============================
(2018-07-10)

Bugs
----
* A missing html_to_plain_text_command is now properly detected and logged.
  (Closes #345)
* Syntactically invalid sender addresses are now ignored.  (Closes #229)
* An AttributeError: 'str' object has no attribute 'decode' exception in
  subject prefixing is fixed.  (Closes #359)
* Messages with no syntactically valid senders are now automatically
  discarded.  (Closes #369)
* Various message holds and rejects that gave 'N/A' as a reason now give an
  appropriate reason.  (Closes #368)
* Bounce messages are now composed for proper translations.
* Messages with badly encoded ``Subject`` headers no longer crash the message
  moderation REST API.  (Closes #383)
* Generated ``regexp`` tables for Postfix now account for possible ``+extra``
  additions to the ``-bounces`` and ``-confirm`` addresses.  (Closes #401)
* Address confirmation notices are now properly encoded in the character set
  of the list's preferred_language.  (Closes #395 and #413)
* Thanks to Jim Popovitch, certain failures in DNS lookups of DMARC policy
  will now result in mitigations being applied.  (Closes #415)
* Messages without a sender can no longer bypass the ``nonmember-moderation``
  rule.  (Closes #414)
* Invalid regexps in header_matches rules are properly logged and can't be set
  via REST.  (Closes #418)
* A list whose name is one of the ``admin``, ``bounces``, ``confirm``, etc.
  subaddresses can now be posted to.  (Closes #433)
* The ``admin`` subaddress, a synonym for ``bounces`` and deprecated since
  Mailman 2.1, has been removed.  (Closes #435)
* Better support for changing the ``list_name`` property.  (Closes #428)
* Raw Message text is now coerced to pure ascii before sending, and
  https://bugs.python.org/issue27321 is now defended against by overriding
  Message.as_string() to cover more cases than before.  (Closes #406)
* The override of Message.as_string() has been extended to catch another
  observed exception.  (Closes #441)
* The email.message.UserNotification() constructor will now not fail if given
  a ``text`` argument containing a character not in the charset of the
  ``lang`` argument.  (Closes #437)
* A new SQLAlchemy column type ``SAUnicodeXL`` has been implemented to support
  large columns in MySQL and is used for the ``value`` column of the
  ``pendedkeyvalue`` table.  (Closes #385)
* Messages with ``Subject`` headers encoded in an unknown character set no
  longer throw ``LookupError`` in subject prefixing.  (Closes #445)
* A list's ``last_post_at`` is now properly updated.  (Closes #453)
* Fixed an AttributeError in mailman/handlers/decorate.py when
  member.subscriber is an ``IUser`` instance rather than an ``IAddress``
  instance.  (Closes #449)
* Message decoration has been removed from the posting pipeline and added to
  bulk delivery to avoid duplicate decoration of personalized and VERPed
  messages.  (Closes #450)
* The ``mailman inject`` command now reads standard input as documented if
  there is no ``-f`` or ``--filename`` option.  (Closes #459)
* Mailman doesn't chmod existing configuration directories on startup (Closes
  #439)
* Calling ``set`` on a template evicts the local cache if the template was
  cached before. (Closes #463)
* The override of Message.as_string() has been extended to catch yet another
  observed exception.  (Closes #470)
* Fixed a typo in the help for ``mailman digests --periodic``.  (Closes #472)
* Character encoding errors in adding headers and footers to multipart messages
  are detected and ``replaced``.  (Closes #409)
* The help for ``mailman qfile`` has been fixed to reference ``mailman qfile``
  rather than the non-existent ``bin/dumpdb``.  (Closes #475)
* The dmarc rule has been fixed to not throw a TypeError when msg.get('from')
  returns a header instance.  (Closes #477)
* ``mailman`` command without any sub-command now invokes ``mailman help`` by
  default. (Closes #479)
* The ``alias_domain`` attribute can become a null string.  ``mta/postfix.py``
  has been fixed to generate proper mappings in this case.  (Closes #485)
* Fix a bug where duplicate address records can be created when a user adds an
  existing address with a different case. (Closes #476)
* Several additional templates can now be set in the ``var/templates``
  hierarchy.  (Closes #486)

Command line
------------
* Adopt the ``click`` package for command line parsing.  This makes the
  command line more consistent and pluggable.  Also, many CLIs that accepted a
  "fqdn list name" (i.e. the posting address of a mailing list), now also
  accept a ``List-ID``.  Every attempt has been made to keep the CLI backward
  compatible, but there may be subtle differences.  (Closes #346)
* If no listname is given, running ``mailman withlist -r`` must name a
  function taking no arguments.  This can be used to introspect Mailman
  outside of the context of a mailing list.
* Fix ``mailman withlist`` command parsing.  (Closes #319)
* Add a new option ``--periodic`` to ``mailman digests`` command. It sends out
  digests for only those Mailing Lists that have ``digest_send_periodic`` option
  set to ``True``. (Closes #384)
* The ``mailman import21`` command now imports DMARC mitigations.
* The ``mailman import21`` command no longer creates templates with
  non-standard names,  (Closes #482)

Configuration
-------------
* The ``[mailman]pre_hook`` and ``[mailman]post_hook`` variables are
  deprecated.  They can still be specified but they will not be run.
* The ``[paths.*]ext_dir`` variable has been removed.
* A new logger has been added called ``logging.plugins``.
* The ``[styles]paths`` variable has been removed; you can now specify
  additional styles using the new plugin architecture.
* Mailman now also searches at ``/etc/mailman3/mailman.cfg`` for the
  configuration file.

Database
--------
* The fix for #313 which ported an upstream SQLAlchemy fix to Mailman
  has been refactored now that SQLAlchemy 1.2 has been released.

Interfaces
----------
* Broaden the semantics for ``IListManager.get()``.  This API now accepts
  both ``List-ID``s and fully qualified list names, since that's the most
  common use case.  There's now a separate ``.get_by_fqdn()`` which only
  accepts the latter and mirrors the already existing ``.get_by_list_id()``.
* A new template ``list:user:notice:rejected`` has been added for customizing
  the bounce message rejection notice.
* The ``acceptable_alias`` and ``require_explicit_destination`` attributes
  have been added to the ``IMailingList`` definition.  (Closes #483)

Other
-----
* Add a new plugin architecture, which allows third parties to add
  initialization hooks, REST endpoints, and additional components.  Given by
  Jan Jancar.
* Drop support for Python 3.4.  (Closes #373)
* Bump minimum requirements for aiosmtpd (>= 1.1) and flufl.lock (>= 3.1).
* Add '.pc' (patch directory) to list of ignored patterns when building the
  documentation with Sphinx.
* Domain objects now have an ``alias_domain`` attribute which is normally
  ``None``, but which can be set to an alternate domain.  This will enable
  the Postfix MTA to generate ``virtual_alias_maps`` which will map list
  addresses in the domain to addresses in the alternate domain, and will
  modify the other generated mappings to use the ``alias_domain``.  The
  ``lmtp`` runner will also accept the alias_domain as an alias for the
  ``email_host``.
* ``ICacheManager`` now allows evicting a single file from cache.

REST
----
* Allow a mailing list's acceptable aliases to be cleared by calling
  ``DELETE`` on the list's ``config/acceptable_aliases`` resource.
  (Closes #394)
* Allow setting ``max_message_size`` for a mailing list. (Closes #417)
* Added new attribute in ``lists/styles`` resource ``styles`` that contains the
  list of all the styles in Core along with their description. ``style_names``
  attribute is now deprecated and will be removed in future versions.
* Add ``display_name`` for ``member`` in order to expose ``member.display_name``.
  (Closes #398)
* Expose ``MailingList.respond_to_post_request`` through REST API. (Closes #420)
* Add a new API ``lists/find`` which returns all the lists related to a
  subscriber. It optionally allows filtering based on a role. (See !388)
* ``IAcceptableAliasSet`` resource now interprets an empty string ('') as an
  empty list ([]). This can be used to clear the list of acceptable aliases of a
  MailingList in a PATCH or PUT request, without having to use a DELETE request.
* Expose ``MailingList.require_explicit_destination`` through REST API.
  (Closes #484)


3.1.0 -- "Between The Wheels"
=============================
(2017-05-25)

Bugs
----
* When the mailing list's ``admin_notify_mchanges`` is True, the list owners
  now get the subscription notification.  (Closes: #1)
* Fix the traceback that occurred when trying to convert a ``text/html``
  subpart to plaintext via the ``mimedel`` handler.  Now, a configuration
  variable ``[mailman]html_to_plain_text_command`` in the ``mailman.cfg`` file
  defines the command to use.  It defaults to ``lynx``.  (Closes: #109)
* Confirmation messages should not be ``Precedence: bulk``.  (Closes #75)
* Fix constraint violations on mailing list deletes affecting PostgreSQL.
  Given by Abhilash Raj.  (Closes #115)
* ``mailman`` command with no subcommand now prints the help text.  Given by
  Abhilash Raj.  (Closes #137)
* The MHonArc archiver must set stdin=PIPE when calling the subprocess.
  Given by Walter Doekes.
* For now, treat ``DeliveryMode.summary_digests`` the same as
  ``.mime_digests``.
  (Closes #141).  Also, don't enqueue a particular digest if there are no
  recipients for that digest.
* For Python versions earlier than 3.5, use a compatibility layer for a
  backported smtpd module which can accept non-UTF-8 data.  (Closes #140)
* Bulk emails are now decorated with headers and footers.  Given by Aurélien
  Bompard.  (Closes #145)
* Core no longer depends on the standalone ``mock`` module.  (Closes: #146)
* The logging of moderation reasons has been fixed.  Given by Aurélien
  Bompard.
* Collapse multiple ``Re:`` in Subject headers.  Given by Mark Sapiro.
  (Closes: #147)
* Added Trove classifiers to setup.py.  (Closes: #152)
* Fix the processing of subscription confirmation messages when the mailing
  list is set to confirm-then-moderate.  (Closes #114)
* Fix ``UnicodeEncodeError`` in the hold chain when sending the authorization
  email to the mailing list moderators.  (Closes: #144)
* Fix traceback in approved handler when the moderator password is None.
  Given by Aurélien Bompard.
* Fix IntegrityErrors raised under PostreSQL when deleting users and
  addresses.  Given by Aurélien Bompard.
* Allow mailing lists to have localhost names with a suffix matching the
  subcommand extensions.  Given by Aurélien Bompard.  (Closes: #168)
* Don't traceback if a nonexistent message-id is deleted from the message
  store.  Given by Aurélien Bompard, tweaked by Barry Warsaw.  (Closes: #167)
* Fix a bug in ``SubscriptionService.find_members()`` when searching for a
  subscribed address that is not linked to a user.  Given by Aurélien Bompard.
* Fix a REST server crash when trying to subscribe a user without a preferred
  address.  (Closes #185)
* Fix membership query when multiple users are subscribed to a mailing list.
  Reported by Darrell Kresge.  (Closes: #190)
* Prevent moderation of messages held for a different list.  (Closes: #161)
* When approving a subscription request via the REST API, for a user who is
  already a member, return an HTTP 409 Conflict code instead of the previous
  server traceback (and resulting HTTP 500 code).  (Closes: #193)
* In decoration URIs (e.g. ``IMailingList.header_uri`` and ``.footer_uri``)
  you should now use the mailing list's List-ID instead of the
  fqdn-listname.  The latter is deprecated.  (Closes #196)
* Trying to subscribe an address as a list owner (or moderator or nonmember)
  which is already subscribed with that role produces a server error.
  Originally given by Anirudh Dahiya.  (Closes #198)
* Cross-posting messages held on both lists no longer fails.  (Closes #176)
* Don't let unknown charsets crash the "approved" rule.  Given by Aurélien
  Bompard.  (Closes #203)
* Don't let crashes in IArchiver plugins break handlers or runners.
  (Closes #208)
* Fix "None" as display name in welcome message.  Given by Aditya Divekar.
  (Closes #194)
* Fix ``mailman shell`` processing of ``$PYTHONSTARTUP``.  (Closes #224)
* Fix query bug for ``SubscriptionService.find_members()`` leading to the
  incorrect number of members being returned.  Given by Aurélien Bompard.
  (Closes #227)
* Fix header match rule suffix inflation.  Given by Aurélien Bompard.
  (Closes #226)
* MIME digests now put the individual message/rfc822 messages inside a
  multipart/digest subpart.  (Closes #234)
* Nonmember subscriptions are removed when one of the addresses controlled by
  a user is subscribed as a member.  Given by Aditya Divekar.  (Closes #237)
* Email address validation is now more compliant with RFC 5321.  (Closes #266)
* A mailing list's ``description`` must not contain newlines.  Given by
  Aurélien Bompard.  (Closes: #273)
* Allow MailingList.info to be set using the REST API.  Given by Aurélien
  Bompard.
* Extend header filters to also check sub-part headers.  (Closes #280)
* Allow REST API to PUT and PATCH domain attributes.  Allows Postorius domain
  edit to work.  (Closes: #290)
* Prevent posting from banned addresses.  Given by Aurélien Bompard.
  (Closes: #283)
* Remove the digest mbox files after the digests are sent.  Given by Aurélien
  Bompard.  (Closes: #259)
* Transmit the moderation reason and expose it in the REST API as the
  ``reason`` attribute.  Given by Aurélien Bompard.
* Don't return a 500 error from the REST API when trying to handle a held
  message with defective content.  Given by Abhilash Raj.  (Closes: #256)
* Delete subscription requests when a mailing list is deleted.  Given by
  Abhilash Raj.  (Closes: #214)
* Messages were shunted when non-ASCII characters appeared in a mailing
  list's description.  Given by Mark Sapiro.  (Closes: #215)
* Fix confirmation of unsubscription requests.  (Closes: #294)
* Fix ``mailman stop`` not stopping some runners due to PEP 475 interaction.
  (Closes: #255)
* Update documentation links for ``config.cfg`` settings.  (Closes: #306)
* Disallow problematic characters in listnames.  (Closes: #311)
* Forward port several content filtering fixes from the 2.1 branch.
  (Closes: #330, #331, #332 and #334)

Configuration
-------------
* Mailing lists can now have their own header matching rules, although
  site-defined rules still take precedence.  Importing a Mailman 2.1 list
  with header matching rules defined will create them in Mailman 3, albeit
  with a few unsupported corner cases.  Definition of new header matching
  rules is not yet exposed through the REST API.  Given by Aurélien Bompard.
* The default languages from Mailman 2.1 have been ported over.  Given by
  Aurélien Bompard.
* There is now a configuration setting to limit the characters that can be
  used in list names.

Command line
------------
* ``mailman create <listname@dom.ain>`` will now create missing domains
  by default.  The ``-d``/``--domain`` option is kept for backward
  compatibility, but now there is a ``-D``/``--no-domain`` option to prevent
  missing domains from being create, forcing an error in those cases.
  Given by Gurkirpal Singh.  (Closes #39)
* ``mailman`` subcommands now properly commit any outstanding transactions.
  (Closes #223)
* ``mailman digests`` has grown ``--verbose`` and ``-dry-run`` options.
* ``mailman shell`` now supports readline history if you set the
  ``[shell]history_file`` variable in mailman.cfg.  Also, many useful names
  are pre-populated in the namespace of the shell.  (Closes: #228)

Database
--------
* MySQL is now an officially supported database.  Given by Abhilash Raj.
* Fix a problem with tracebacks when a PostgreSQL database is power cycled
  while Mailman is still running.  This ports an upstream SQLAlchemy fix to
  Mailman in lieu of a future SQLAlchemy 1.2 release.  (Closes: #313)

Interfaces
----------
* Implement reasons for why a message is being held for moderator approval.
  Given by Aurélien Bompard, tweaked by Barry Warsaw.
* The default ``postauth.txt`` and ``postheld.txt`` templates now no longer
  include the inaccurate admindb and confirmation urls.
* Messages now include a ``Message-ID-Hash`` as the replacement for
  ``X-Message-ID-Hash`` although the latter is still included for backward
  compatibility.  Also be sure that all places which add the header use the
  same algorithm.  (Closes #118)
* ``IMessageStore.delete_message()`` no longer raises a ``LookupError`` when
  you attempt to delete a nonexistent message from the message store.
* ``ISubscriptionService.find_members()`` accepts asterisks as wildcards in
  the ``subscriber`` argument string.  Given by Aurélien Bompard.
* ``ISubscriptionService`` now supports mass unsubscribes.  Given by Harshit
  Bansal.

Message handling
----------------
* New DMARC mitigations have been added.  Given by Mark Sapiro.  (Closes #247)
* New placeholders have been added for message headers and footers.  You can
  use a placeholder of the format ``$<archiver-name>_url`` to insert the
  permalink to the message in the named archiver, for any archiver enabled
  for the mailing list.  Given by Abhilash Raj.
* The default posting chain has been modified so that the header-match chain
  and nonmember-moderation rule are processed before "hold" rules are
  processed.  This allows for better anti-spam defenses and rejecting
  non-member posts instead of always holding them for moderator review.
  Given by Aurélien Bompard.  (Closes #163)
* Bounces can now contain rejection messages.  Given by Aurélien Bompard.
* The ``moderation_action`` for members and nonmember can now be ``None``
  which signals falling back to the appropriate list default action,
  e.g. ``default_member_action`` and ``default_nonmember_action``.  Given by
  Aurélien Bompard.  (Closes #189)
* Ensure that postings from alternative emails aren't held for moderator
  approval.  For example, if a user is subscribed with one email but posts
  with a second email that they control, the message should be processed as
  a posting from a member.  Given by Aditya Divekar.  (Closes #222)
* The default message footer has been improved to include a way to
  unsubscribe via the ``-leave`` address.  Given by Francesco Ariis.

REST
----
* REST API version 3.1 introduced.  Mostly backward compatible with version
  3.0 except that UUIDs are represented as hex strings instead of 128-bit
  integers, since the latter are not compatible with all versions of
  JavaScript.  (Closes #121)
* REST clients must minimally support HTTP/1.1. (Closes #288)
* Experimental Gunicorn support.  See ``contrib/gunicorn.py`` docstring for
  details.  With assistance from Eric Searcy.  (Closes #287)
* The new template system is introduced for API 3.1.  See
  ``src/mailman/rest/docs/templates.rst`` for details.  (Closes #249)
* When creating a user via REST using an address that already exists, but
  isn't linked, the address is linked to the new user.  Given by Aurélien
  Bompard.
* The REST API incorrectly parsed ``is_server_owner`` values when given
  explicitly in the POST that creates a user.  (Closes #136)
* A new top-level resource ``<api>/owners`` can be used to get the list of
  server owners as ``IUser`` s.  (Closes #135)
* By POSTing to a user resource with an existing unlinked address, you can
  link the address to the user.  Given by Abhilash Raj.
* Fix pagination values ``start`` and ``total_size`` in the REST API.  Given
  by Aurélien Bompard.  (Closes: #154)
* JSON representations for held message now include a ``self_link``.
* When ``[devmode]enabled`` is set, the JSON output is sorted.  Given by
  Aurélien Bompard.
* A member's moderation action can be changed via the REST API.  Given by
  Aurélien Bompard.
* Fixed a number of corner cases for the return codes when PUTing or PATCHing
  list configuration variables.  (Closes: #182)
* Expose ``digest_send_periodic``, ``digest_volume_frequency``, and
  ``digests_enabled`` (renamed from ``digestable``) to the REST API.
  (Closes: #159)
* Expose the "bump digest" and "send digest" functionality though the REST
  API via the ``<api>/lists/<list-id>/digest`` end-point.  GETting this
  resource returns the ``next_digest_number`` and ``volume`` as the same
  values accessible through the list's configuraiton resource.  POSTing to
  the resource with either ``send=True``, ``bump=True``, or both invokes the
  given action.
* Global and list-centric bans can now be managed through the REST API.
  Given by Aurélien Bompard.
* ``<api>/members/find`` accepts GET query parameters in addition to POST
  arguments.  Given by Aurélien Bompard.
* Header match rules for individual mailing lists are now exposed in the REST
  API.  Given by Aurélien Bompard.  (Closes: #192)
* Expose ``goodbye_message_uri`` in the REST API.  Given by Harshit Bansal.
* New subscription requests are rejected if there is already one pending.
  With thanks to Anirudh Dahiya.  (Closes #199)
* Expose the system pipelines and chains via ``<api>/system/pipelines`` and
  ``<api>/system/chains`` respectively.  Given by Simon Hanna.  (Closes #66)
* Support mass unsubscription of members via ``DELETE`` on the
  ``<api>/lists/<list-id>/roster/member`` resource.  Given by Harshit
  Bansal.  (Closes #171)
* It is now possible to merge users when creating them via REST.  When you
  POST to ``<api>/users/<address>/addresses`` and the address given in the
  ``email`` parameter already exists, instead of getting a 400 error, if you
  set ``absorb_existing=True`` in the POST data, the existing user will be
  merged into the newly created on.  Given by Aurélien Bompard.
* Port to Falcon 1.0 (Closes #20)
* A member's ``moderation_action`` can be reset, allowing fallback to the
  list's ``default_member_action`` by setting the attribute to the empty
  string in the REST API.  Given by Aurélien Bompard.
* A list's ``moderator_password`` can be set via the REST API.  Given by
  Andrew Breksa.  (Closes #207)
* The ban manager now returns a pageable, sorted sequence.  Given by Amit and
  Aurélien Bompard.  (Closes #284)
* Query parameters now allow you to filter mailing lists by the
  ``advertised`` boolean parameter.  Given by Aurélien Bompard.
* Only the system-enabled archivers are returned in the REST API.  Given by
  Aurélien Bompard.
* **Backward incompatibility: mild** Held message resources now have an
  ``original_subject`` key which is the raw value of the ``Subject:`` header
  (i.e. without any RFC 2047 decoding).  The ``subject`` key is RFC 2047
  decoded.  Given by Simon Hanna.  (Closes #219)

Other
-----
* Add official support for Python 3.5 and 3.6. (Closes #295)
* A handful of unused legacy exceptions have been removed.  The redundant
  ``MailmanException`` has been removed; use ``MailmanError`` everywhere.
* Drop the use of the ``lazr.smtptest`` library, which is based on the
  asynchat/asyncore-based smtpd.py stdlib module.  Instead, use the
  asyncio-based `aiosmtpd <https://aiosmtpd.readthedocs.io/>`_ package.
* Improvements in importing Mailman 2.1 lists, given by Aurélien Bompard.
* The ``prototype`` archiver is not web accessible so it does not have a
  ``list_url`` or permalink.  Given by Aurélien Bompard.
* Large performance improvement in ``SubscriptionService.find_members()``.
  Given by Aurélien Bompard.
* Rework the digest machinery, and add a new ``digests`` subcommand, which
  can be used from the command line or cron to immediately send out any
  partially collected digests, or bump the digest and volume numbers.
* The mailing list "data directory" has been renamed.  Instead of using the
  fqdn listname, the subdirectory inside ``[paths]list_data_dir`` now uses
  the List-ID.
* The ``mailman members`` command can now be used to display members based on
  subscription roles.  Also, the positional "list" argument can now accept
  list names or list-ids.
* Unsubscriptions can now be confirmed and/or moderated.  (Closes #213)


3.0.0 -- "Show Don't Tell"
==========================
(2015-04-28)

Architecture
------------
* Domains now have a list of owners, which are ``IUser`` objects, instead of
  the single ``contact_address`` they used to have.  ``IUser`` objects now
  also have a ``is_server_owner`` flag (defaulting to False) to indicate
  whether they have superuser privileges.  Give by Abhliash Raj, with fixes
  and refinements by Barry Warsaw.  (LP: #1423756)
* Mailing list subscription policy work flow has been completely rewritten.
  It now properly supports email verification and subscription confirmation
  by the user, and approval by the moderator using unique tokens.
  ``IMailingList`` objects now have a ``subscription_policy`` attribute.
  (LP: #1095552)
* Port the REST machinery to Falcon 0.3. (LP: #1446881)

Bugs
----
* Fix calculation of default configuration file to use when the ``$var_dir``
  is created by ``mailman start``.  (LP: #1411435)
* When creating a user with an email address, do not create the user record
  if the email address already exists.  Given by Andrew Stuart.
  (LP: #1418280)
* When deleting a user via REST, make sure all linked addresses are deleted.
  Found by Andrew Stuart.  (LP: #1419519)
* When trying to subscribe an address to a mailing list through the REST API
  where a case-differing version of the address is already subscribed, return
  a 409 error instead of a 500 error.  Found by Ankush Sharma.  (LP: #1425359)
* ``mailman lists --domain`` was not properly handling its arguments.  Given
  by Manish Gill.  (LP: #1166911)
* When deleting a user object, make sure their preferences are also deleted.
  Given by Abhishek.  (LP: #1418276)
* Be sure a mailing list's acceptable aliases are deleted when the mailing
  list itself is deleted.  (LP: #1432239)
* The built-in example ``IArchiver`` implementations now explicitly return
  None.  (LP: #1203359)
* The test suite now runs successfully again with PostgreSQL.  Given by
  Aurélien Bompard.  (LP: #1435941)

Configuration
-------------
* When specifying a file system path in the [paths.*] section, $cfg_file can
  be used to expand into the path of the ``-C`` option if given.  In the
  default ``[paths.dev]`` section, ``$var_dir`` is now specified relative to
  ``$cfg_file`` so that it won't accidentally be relative to the current
  working directory, if ``-C`` is given.
* ``$cwd`` is now an additional substitution variable for the ``mailman.cfg``
  file's ``[paths.*]`` sections.  A new ``[paths.here]`` section is added,
  which puts the ``var_dir`` in ``$cwd``.  It is made the default layout.

Documentation
-------------
* Improve the documentation describing how to run Alembic to add new schema
  migrations.  Given by Abhilash Raj.

REST
----
* **Backward incompatible change**: The JSON representation for pending
  mailing list subscription hold now no longer includes the ``password``
  key.  Also, the ``address`` key has been renamed ``email`` for consistent
  terminology and other usage.
* You can now view the contents of, inject messages into, and delete messages
  from the various queue directories via the ``<api>/queues`` resource.
* You can now DELETE an address.  If the address is linked to a user, the
  user is not delete, it is just unlinked.
* A new API is provided to support non-production testing infrastructures,
  allowing a client to cull all orphaned UIDs via ``DELETE`` on
  ``<api>/reserved/uids/orphans``.  Note that *no guarantees* of API
  stability will ever be made for resources under ``reserved``.
  (LP: #1420083)
* Domains can now optionally be created with owners; domain owners can be
  added after the fact; domain owners can be deleted.  Also, users now have
  an ``is_server_owner`` flag as part of their representation, which defaults
  to False, and can be PUT and PATCH'd.  Given by Abhilash Raj, with fixes
  and refinements by Barry Warsaw.  (LP: #1423756)


3.0 beta 5 -- "Carve Away The Stone"
====================================
(2014-12-29)

Bugs
----
* Fixed Unicode errors in the digest runner and when sending messages to the
  site owner as a fallback.  Given by Aurélien Bompard.  (LP: #1130957).
* Fixed Unicode errors when a message being added to the digest has non-ascii
  characters in its payload, but no Content-Type header defining a charset.
  Given by Aurélien Bompard.  (LP: #1170347)
* Fixed messages without a `text/plain` part crashing the `Approved` rule.
  Given by Aurélien Bompard.  (LP: #1158721)
* Fixed getting non-ASCII filenames from RFC 2231 i18n'd messages.  Given by
  Aurélien Bompard.  (LP: #1060951)
* Fixed `AttributeError` on MIME digest messages.  Given by Aurélien Bompard.
  (LP: #1130696)

Commands
--------
* The `mailman conf` command no longer takes the `-t/--sort` option; the
  output is always sorted.

Configuration
-------------
* The ``[database]migrations_path`` setting is removed.

Database
--------
* The ORM layer, previously implemented with Storm, has been replaced by
  SQLAlchemy, thanks to the fantastic work by Abhilash Raj and Aurélien
  Bompard.  Alembic is now used for all database schema migrations.
* The new logger `mailman.database` logs any errors at the database layer.

Development
-----------
* Python 3.4 is now the minimum requirement.
* You no longer have to create a virtual environment separately when running
  the test suite.  Just use `tox`.
* You no longer have to edit `src/mailman/testing/testing.cfg` to run the
  test suite against PostgreSQL.  See `src/mailman/docs/START.rst` for
  details.

Interfaces
----------
* The RFC 2369 headers added to outgoing messages are now added in sorted
  order.
* Several changes to the internal API:

  - `IListManager.mailing_lists` is guaranteed to be sorted in List-ID order.
  - `IDomains.mailing_lists` is guaranteed to be sorted in List-ID order.
  - Iteration over domains via the `IDomainManager` is guaranteed to be sorted
    by `IDomain.mail_host` order.
  - `ITemporaryDatabase` interface and all implementations are removed.

REST
----
* The Falcon Framework has replaced restish as the REST layer.  This is an
  internal change only.
* The JSON representation `http_etag` key uses an algorithm that is
  insensitive to Python's dictionary sort order.
* The address resource now has an additional '/user' sub-resource which can
  be used to GET the address's linked user if there is one.  This
  sub-resource also supports POST to link an unlinked address (with an
  optional 'auto_create' flag), and PUT to link the address to a different
  user.  It also supports DELETE to unlink the address.  (LP: #1312884)
  Given by Aurélien Bompard based on work by Nicolas Karageuzian.
* The ``/3.0/system`` path is deprecated; use ``/3.0/system/versions`` to get
  the system version information.
* You can access the system configuration via the resource path
  ``/3.0/system/configuration/<section>``.  This returns a dictionary with
  the keys being the section's variables and the values being their value
  from ``mailman.cfg`` as verbatim strings.  You can get a list of all
  section names via ``/3.0/system/configuration`` which returns a dictionary
  containing the ``http_etag`` and the section names as a sorted list under
  the ``sections`` key.  The system configuration resource is read-only.
* Member resource JSON now include the ``member_id`` as a separate key.


3.0 beta 4 -- "Time and Motion"
===============================
(2014-04-22)

Development
-----------
* Mailman 3 no longer uses ``zc.buildout`` and tests are now run by the
  ``nose2`` test runner.  See ``src/mailman/docs/START.rst`` for details on
  how to build Mailman and run the test suite.  Also, use ``-P`` to select a
  test pattern and ``-E`` to enable stderr debugging in runners.
* Use the ``enum34`` package instead of ``flufl.enum``.
* Use ``setuptools`` instead of ``distribute``, since the latter is defunct.

REST
----
* Add ``reply_to_address`` and ``first_strip_reply_to`` as writable
  attributes of a mailing list's configuration.  (LP: #1157881)
* Support pagination of some large collections (lists, users, members).
  [Florian Fuchs]  (LP: #1156529)
* Expose ``hide_address`` to the ``.../preferences`` REST API.
  [Sneha Priscilla.]  (LP: #1203519)
* Mailing lists can now individually enable or disable any archiver available
  site-wide.  [Joanna Skrzeszewska]  (LP: #1158040)
* Addresses can be added to existing users, including display names, via the
  REST API.  [Florian Fuchs]
* Fixed a crash in the REST server when searching for nonmembers via
  ``/find`` which we've never seen before, because those members only have an
  address record, not a user record.  This requires a small change in the API
  where the JSON response's ``address`` key now contains the URL to the
  address resource, the new ``email`` key contains the email address as a
  string, and the ``user`` key is optional.

Commands
--------
* `mailman conf` now has a `-t/--sort` flag which sorts the output by section
  and then key.  [Karl-Aksel Puulmann and David Soto] (LP: 1162492)
* Greatly improve the fidelity of the Mailman 2.1 list importer functionality
  (i.e. ``mailman import21``).  [Aurélien Bompard].

Configuration
-------------
* Add support for the Exim 4 MTA.  [Stephen Turnbull]
* When creating the initial file system layout in ``var``, e.g. via
  ``bin/mailman info``, add an ``var/etc/mailman.cfg`` file if one does not
  already exist.  Also, when initializing the system, look for that file as
  the configuration file, just after ``./mailman.cfg`` and before
  ``~/.mailman.cfg``.  (LP: #1157861)

Database
--------
* The `bounceevent` table now uses list-ids to cross-reference the mailing
  list, to match other tables.  Similarly for the `IBounceEvent` interface.
* Added a `listarchiver` table to support list-specific archivers.

Bugs
----
* Non-queue runners should not create ``var/queue`` subdirectories.
  [Sandesh Kumar Agrawal] (LP: #1095422)
* Creation of lists with upper case names should be coerced to lower case.
  (LP: #1117176)
* Fix REST server crash on `mailman reopen` due to no interception of
  signals.  (LP: #1184376)
* Add `subject_prefix` to the `IMailingList` interface, and clarify the
  docstring for `display_name`.  (LP: #1181498)
* Fix importation from MM2.1 to MM3 of the archive policy.
  [Aurélien Bompard] (LP: #1227658)
* Fix non-member moderation rule to prefer a member sender if both members
  and non-members are in the message's sender list.  [Aurélien Bompard]
  (LP: #1291452)
* Fix IntegrityError (against PostgreSQL) when deleting a list with content
  filters.  [Aurélien Bompard]  (LP: #1117174)
* Fix test isolation bug in ``languages.rst``.
  [Piotr Kasprzyk] (LP: #1308769)


3.0 beta 3 -- "Here Again"
==========================
(2012-12-31)

Compatibility
-------------
* Python 2.7 is now required.  Python 2.6 is no longer officially supported.
  The code base is now also `python2.7 -3` clean, although there are still
  some warnings in 3rd party dependencies.  (LP: #1073506)

REST
----
* **API change**: The JSON representation for held messages no longer
  includes the `data` key.  The values in this dictionary are flatted into
  the top-level JSON representation.  The `key` key is remove since it's
  redundant.  Use `message_id` for held messages, and `address` for held
  subscriptions/unsubscriptions.  The following `_mod_*` keys are inserted
  without the `_mod_` prefix:

  - `_mod_subject` -> `subject`
  - `_mod_hold_date` -> `hold_date`
  - `_mod_reason` -> `reason`
  - `_mod_sender` -> `sender`
  - `_mod_message_id` -> `message_id`

* List styles are supported through the REST API.  Get the list of available
  styles (by name) via `.../lists/styles`.  Create a list in a specific style
  by using POST data `style_name=<style>`.  (LP: #975692)
* Allow the getting/setting of IMailingList.subject_prefix via the REST API
  (given by Terri Oda).  (LP: #1062893)
* Expose a REST API for membership change (subscriptions and unsubscriptions)
  moderation.  (LP: #1090753)
* Add list_id to JSON representation for a mailing list (given by Jimmy
  Bergman).
* The canonical resource for a mailing list (and thus its self_link) is now
  the URL with the list-id.  To reference a mailing list, the list-id url is
  preferred, but for backward compatibility, the posting address is still
  accepted.
* You can now PUT and PATCH on user resources to change the user's display
  name or password.  For passwords, you pass in the clear text password and
  Mailman will hash it before storing.
* You can now verify and unverify an email address through the REST API.
  POST to .../addresses/<email>/verify and .../addresses/<email>/unverify
  respectively.  The POST data is ignored.  It is not an error to verify or
  unverify an address more than once, but verifying an already verified
  address does not change its `.verified_on` date.  (LP: #1054730)
* Deleting a user through the REST API also deletes all the user's linked
  addresses and memberships.  (LP: #1074374)
* A user's password can be verified by POSTing to .../user/<id>/login.  The
  data must contain a single parameter `cleartext_password` and if this
  matches, a 204 (No Content) will be returned, otherwise a 403 (Forbidden)
  is returned.  (LP: #1065447)

Configuration
-------------
* `[passlib]path` configuration variable renamed to `[passlib]configuration`.
* Postfix-specific configurations in the `[mta]` section are moved to a
  separate file, named by the `[mta]configuration` variable.
* In the new `postfix.cfg` file, `postfix_map_cmd` is renamed to
  `postmap_command`.
* The default list style is renamed to `legacy-default` and a new
  `legacy-announce` style is added.  This is similar to the `legacy-default`
  except set up for announce-only lists.

Database
--------
* The `ban` table now uses list-ids to cross-reference the mailing list,
  since these cannot change even if the mailing list is moved or renamed.
* The following columns were unused and have been removed:

  - `mailinglist.new_member_options`
  - `mailinglist.send_reminders`
  - `mailinglist.subscribe_policy`
  - `mailinglist.unsubscribe_policy`
  - `mailinglist.subscribe_auto_approval`
  - `mailinglist.private_roster`
  - `mailinglist.admin_member_chunksize`

Interfaces
----------
* The `IBanManager` is no longer a global utility.  Instead, you adapt an
  `IMailingList` to an `IBanManager` to manage the bans for a specific
  mailing list.  To manage the global bans, adapt ``None``.

Commands
--------
* `bin/mailman aliases` loses the `--output`, `--format`, and `--simple`
  arguments, and adds a `--directory` argument.  This is necessary to support
  the Postfix `relay_domains` support.
* `bin/mailman start` was passing the wrong relative path to its runner
  subprocesses when -C was given.  (LP: #982551)
* `bin/runner` command has been simplified and its command line options
  reduced.  Now, only one `-r/--runner` option may be provided and the
  round-robin feature has been removed.

Other
-----
* Added support for Postfix `relay_domains` setting for better virtual domain
  support.  [Jimmy Bergman].
* Two new events are triggered on membership changes: `SubscriptionEvent`
  when a new member joins a mailing list, and an `UnsubscriptionEvent` when a
  member leaves a mailing list.  (LP: #1047286)
* Improve the --help text for the `start`, `stop`, `restart`, and `reopen`
  subcommands.  (LP: #1035033)

Bugs
----
* Fixed `send_goodbye_message()`.  (LP: #1091321)
* Fixed REST server crash on `reopen` command.  Identification and test
  provided by Aurélien Bompard.  (LP: #1184376)


3.0 beta 2 -- "Freeze"
======================
(2012-09-05)

Architecture
------------
* The link between members and the mailing lists they are subscribed to, is
  now via the RFC 2369 `list_id` instead of the fqdn listname (i.e. posting
  address).  This is because while the posting address can change if the
  mailing list is moved to a new server, the list id is fixed.
  (LP: #1024509)

  - IListManager.get_by_list_id() added.
  - IListManager.list_ids added.
  - IMailingList.list_id added.
  - Several internal APIs that accepted fqdn list names now require list ids,
    e.g. ISubscriptionService.join() and .find_members().
  - IMember.list_id attribute added; .mailing_list is now an alias that
    retrieves and returns the IMailingList.

* `passlib`_ is now used for all password hashing instead of flufl.password.
  The default hash is `sha512_crypt`.  (LP: #1015758)
* Internally, all datetimes are kept in the UTC timezone, however because of
  LP: #280708, they are stored in the database in naive format.
* `received_time` is now added to the message metadata by the LMTP runner
  instead of by `Switchboard.enqueue()`.  This latter no longer depends on
  `received_time` in the metadata.
* The `ArchiveRunner` no longer acquires a lock before it calls the
  individual archiver implementations, since not all of them need a lock.  If
  they do, the implementations must acquire said lock themselves.
* The `news` runner and queue has been renamed to the more accurate `nntp`.
  The runner has also been ported to Mailman 3 (LP: #967409).  Beta testers
  can safely remove `$var_dir/queue/news`.
* A mailing list's *moderator password* is no longer stored in the clear; it
  is hashed with the currently selected scheme.
* An `AddressVerificationEvent` is triggered when an `IAddress` is verified
  or unverified.  (LP: #975698)
* A `PasswordChangeEvent` is triggered when an `IUser`'s password changes.
  (LP: #975700)
* When a queue runner gets an exception in its _dispose() method, a
  `RunnerCrashEvent` is triggered, which contains references to the queue
  runner, mailing list, message, metadata, and exception.  Interested parties
  can subscribe to that `zope.event` for notification.
* Events renamed and moved:
  * `mailman.chains.accept.AcceptNotification`
  * `mailman.chains.base.ChainNotification`
  * `mailman.chains.discard.DiscardNotification`
  * `mailman.chains.hold.HoldNotification`
  * `mailman.chains.owner.OwnerNotification`
  * `mailman.chains.reject.RejectNotification`
  changed to (respectively):
  * `mailman.interfaces.chains.AcceptEvent`
  * `mailman.interfaces.chains.ChainEvent`
  * `mailman.interfaces.chains.DiscardEvent`
  * `mailman.interfaces.chains.HoldEvent`
  * `mailman.interfaces.chains.AcceptOwnerEvent`
  * `mailman.interfaces.chains.RejectEvent`
* A `ConfigurationUpdatedEvent` is triggered when the system-wide global
  configuration stack is pushed or popped.
* The policy for archiving has now been collapsed into a single enum, called
  ArchivePolicy.  This describes the three states of never archive, archive
  privately, and archive_publicly. (LP: #967238)

Database
--------
* Schema migrations (LP: #971013)

  - mailinglist.include_list_post_header -> allow_list_posts
  - mailinglist.news_prefix_subject_too  -> nntp_prefix_subject_too
  - mailinglist.news_moderation          -> newsgroup_moderation
  - mailinglist.archive and mailinglist.archive_private have been collapsed
    into archive_policy.
  - mailinglist.nntp_host has been removed.
  - mailinglist.generic_nonmember_action has been removed (LP: #975696)

* Schema migrations (LP: #1024509)
  - member.mailing_list -> list_id
* The PostgreSQL port of the schema accidentally added a moderation_callback
  column to the mailinglist table.  Since this is unused in Mailman, it was
  simply commented out of the base schema for PostgreSQL.

REST
----
* Expose `archive_policy` in the REST API.  Contributed by Alexander
  Sulfrian.  (LP: #1039129)

Configuration
-------------
* New configuration variables `clobber_date` and `clobber_skew` supported in
  every `[archiver.<name>]` section.  These are used to determine under what
  circumstances a message destined for a specific archiver should have its
  `Date:` header clobbered.  (LP: #963612)
* With the switch to `passlib`_, `[passwords]password_scheme` has been
  removed.  Instead use `[passwords]path` to specify where to find the
  `passlib.cfg` file.  See the comments in `schema.cfg` for details.
* Configuration schema variable changes:
  * [nntp]username -> [nntp]user
  * [nntp]port (added)
* Header check specifications in the `mailman.cfg` file have changed quite
  bit.  The previous `[spam.header.foo]` sections have been removed.
  Instead, there's a new `[antispam]` section that contains a `header_checks`
  variable.  This variable takes multiple lines of `Header: regexp` values,
  one per line.  There is also a new `jump_chain` variable which names the
  chain to jump to should any of the header checks (including the
  list-specific, and programmatically added ones) match.

Documentation
-------------
* Some additional documentation on related components such as Postorius and
  hyperkitty have been added, given by Stephen J Turnbull.

Bug fixes
---------
* Fixed the RFC 1153 digest footer to be compliant.  (LP: #887610)
* Fixed a UnicodeError with non-ascii message bodies in the `approved` rule,
  given by Mark Sapiro. (LP: #949924)
* Fixed a typo when returning the configuration file's header match checks.
  (LP: #953497)
* List-Post should be NO when posting is not allowed. (LP: #987563)
* Non-unicode values in msgdata broke pending requests. (LP: #1031391)
* Show devmode in `bin/mailman info` output. (LP: #1035028)
* Fix residual references to the old `IMailingList` archive variables.
  (LP: #1031393)

.. _`passlib`: https://passlib.readthedocs.io/en/stable/index.html


3.0 beta 1 -- "The Twilight Zone"
=================================
(2012-03-23)

Architecture
------------
* Schema migrations have been implemented.
* Implement the style manager as a utility instead of an attribute hanging
  off the `mailman.config.config` object.
* PostgreSQL support contributed by Stephen A. Goss. (LP: #860159)
* Separate out the RFC 2369 header adding handler.
* Dynamically calculate the `List-Id` header instead of storing it in the
  database.  This means it cannot be changed.
* Major redesign of the template search system, fixing LP: #788309.  $var_dir
  is now used when search for all template overrides, site, domain, or
  mailing list.  The in-tree English templates are used only as a last
  fallback.
* Support downloading templates by URI, including mailman:// URIs.  This is
  used in welcome and goodbye messages, as well as regular and digest headers
  and footers, and supports both language and mailing list specifications.
  E.g. mailman:///test@example.com/it/welcome.txt
* $user_password is no longer supported as a placeholder in headers and
  footers.
* Mailing lists get multiple chains and pipelines.  For example, normal
  postings go through the `posting_chain` while messages to owners to through
  `owners_chain`.  The default `built-in` chain is renamed to
  `default-posting-chain` while the `built-in` pipeline is renamed
  `default-posting-pipeline`.
* The experimental `maildir` runner is removed.  Use LMTP.
* The LMTP server now requires that the incoming message have a `Message-ID`,
  otherwise it rejects the message with a 550 error.  Also, the LMTP server
  adds the `X-Message-ID-Hash` header automatically.  The `inject` cli
  command will also add the `X-Message-ID-Hash` header, but it will craft a
  `Message-ID` header first if one is missing from the injected text.  Also,
  `inject` will always set the correct value for the `original_size`
  attribute on the message object, instead of trusting a possibly incorrect
  value if it's already set.  The individual `IArchiver` implementations no
  longer set the `X-Message-ID-Hash` header.
* The Prototype archiver now stores its files in maildir format inside of
  `$var_dir/archives/prototype`, given by Toshio Kuratomi.
* Improved "8 mile high" document distilled by Stephen J Turnbull from the
  Pycon 2012 Mailman 3 sprint.  Also improvements to the Sphinx build given
  by Andrea Crotti (LP: #954718).
* Pipermail has been eradicated.
* Configuration variable `[mailman]filtered_messages_are_preservable`
  controls whether messages which have their top-level `Content-Type`
  filtered out can be preserved in the `bad` queue by list owners.
* Configuration section `[scrubber]` removed, as is the scrubber handler.
  This handler was essentially incompatible with Mailman 3 since it required
  coordination with Pipermail to store attachments on disk.

Database
--------
* Schema changes:
  - welcome_msg      -> welcome_message_uri
  - goodbye_msg      -> goodbye_message_uri
  - send_welcome_msg -> send_welcome_message
  - send_goodbye_msg -> send_goodbye_message
  - msg_header       -> header_uri
  - msg_footer       -> footer_uri
  - digest_header    -> digest_header_uri
  - digest_footer    -> digest_footer_uri
  - start_chain      -> posting_chain
  - pipeline         -> posting_pipeline
  - real_name        -> display_name (mailinglist, user, address)
* Schema additions:
  - mailinglist.filter_action
  - mailinglist.owner_chain
  - mailinglist.owner_pipeline

REST
----
* Held messages can now be moderated through the REST API.  Mailing list
  resources now accept a `held` path component.  GETing this returns all held
  messages for the mailing list.  POSTing to a specific request id under this
  url can dispose of the message using `Action` enums.
* Mailing list resources now have a `member_count` attribute which gives the
  number of subscribed members.  Given by Toshio Kuratomi.

Interfaces
----------
* Add property `IUserManager.members` to return all `IMembers` in the system.
* Add property `IListmanager.name_components` which returns 2-tuples for
  every mailing list as (list_name, mail_host).
* Remove previously deprecated `IListManager.get_mailing_lists()`.
* `IMailTransportAgentAliases` now explicitly accepts duck-typed arguments.
* `IRequests` interface is removed.  Now just use adaptation from
  `IListRequests` directly (which takes an `IMailingList` object).
* `handle_message()` now allows for `Action.hold` which is synonymous with
  `Action.defer` (since the message is already being held).
* `IListRequests.get_request()` now takes an optional `request_type`
  argument to narrow the search for the given request.
* New `ITemplateLoader` utility.
* `ILanguageManager.add()` returns the `ILanguage` object just created.
* `IMailinglist.decorators` removed; it was unused
* `IMailingList.real_name` -> `IMailingList.display_name`
* `IUser.real_name` -> `IUser.display_name`
* `IAddress.real_name` -> `IAddress.display_name`
* Add property `IRoster.member_count`.

Commands
--------
* IPython support in `bin/mailman shell` contributed by Andrea Crotti.
  (LP: #949926).
* The `mailman.cfg` configuration file will now automatically be detected if
  it exists in an `etc` directory which is a sibling of argv0.
* `bin/mailman shell` is an alias for `withlist`.
* The `confirm` email command now properly handles `Re:`-like prefixes, even
  if they contain non-ASCII characters.  (LP: #685261)
* The `join` email command no longer accepts an `address=` argument.  Its
  `digest=` argument now accepts the following values: `no` (for regular
  delivery), `mime`, or `plain`.
* Added a `help` email command.
* A welcome message is sent when the user confirms their subscription via
  email.
* Global ``-C`` option now accepts an absolute path to the configuration
  file.  Given by Andrea Crotti.  (LP: #953707)

Bug fixes
---------
* Subscription disabled probe warning notification messages are now sent
  without a `Precedence:` header.  Given by Mark Sapiro. (LP: #808821)
* Fixed KeyError in retry runner, contributed by Stephen A. Goss.
  (LP: #872391)
* Fixed bogus use of `bounce_processing` attribute (should have been
  `process_bounces`, with thanks to Vincent Fretin.  (LP: #876774)
* Fix `test_moderation` for timezones east of UTC+0000, given by blacktav.
  (LP: #890675)


3.0 alpha 8 -- "Where's My Thing?"
==================================
(2011-09-23)

Architecture
------------
* Factor out bounce detection to `flufl.bounce`.
* Unrecognized bounces can now also be forwarded to the site owner.
* mailman.qrunner log is renamed to mailman.runner
* master-qrunner.lck -> master.lck
* master-qrunner.pid -> master.pid
* Four new events are created, and notifications are sent during mailing list
  lifecycle changes:
  - ListCreatingEvent - sent before the mailing list is created
  - ListCreatedEvent  - sent after the mailing list is created
  - ListDeletingEvent - sent before the mailing list is deleted
  - ListDeletedEvent  - sent after the mailing list is deleted
* Four new events are created, and notifications are sent during domain
  lifecycle changes:
  - DomainCreatingEvent - sent before the domain is created
  - DomainCreatedEvent  - sent after the domain is created
  - DomainDeletingEvent - sent before the domain is deleted
  - DomainDeletedEvent  - sent after the domain is deleted
* Using the above events, when a domain is deleted, associated mailing lists
  are deleted.  (LP: #837526)
* IDomain.email_host -> .mail_host (LP: #831660)
* User and Member ids are now proper UUIDs.
* Improved the way enums are stored in the database, so that they are more
  explicitly expressed in the code, and more database efficient.

REST
----
* Preferences for addresses, users, and members can be accessed, changed, and
  deleted through the REST interface.  Hierarchical, combined preferences for
  members, and system preferences can be read through the REST interface.
  (LP: #821438)
* The IMailingList attribute ``host_name`` has been renamed to ``mail_host``
  for consistency.  This changes the REST API for mailing list
  resources. (LP: #787599)
* New REST resource http://.../members/find can be POSTed to in order to find
  member records.  Optional arguments are `subscriber` (email address to
  search for), `fqdn_listname`, and `role` (i.e. MemberRole).  (LP: #799612)
* You can now query or change a member's `delivery_mode` attribute through
  the REST API (LP: #833132).  Given by Stephen A. Goss.
* New REST resource http://.../<domain>/lists can be GETed in order to find
  all the mailing lists in a specific domain (LP: #829765).  Given by
  Stephen A. Goss.
* Fixed /lists/<fqdn_listname>/<role>/<email> (LP: #825570)
* Remove role plurals from /lists/<fqdn_listname/rosters/<role>
* Fixed incorrect error code for /members/<bogus> (LP: #821020).  Given by
  Stephen A. Goss.
* DELETE users via the REST API.  (LP: #820660)
* Moderators and owners can be added via REST (LP: #834130).  Given by
  Stephen A. Goss.
* Getting the roster or configuration of a nonexistent list did not give a
  404 error (LP: #837676).  Given by Stephen A. Goss.
* PATCHing an invalid attribute on a member did not give a 400 error
  (LP: #833376).  Given by Stephen A. Goss.
* Getting the memberships for a non-existent address did not give a 404 error
  (LP: #848103).  Given by Stephen A. Goss.

Commands
--------
* `bin/qrunner` is renamed to `bin/runner`.
* `bin/mailman aliases` gains `-f` and `-s` options.
* `bin/mailman create` no longer allows a list to be created with bogus owner
  addresses.  (LP: #778687)
* `bin/mailman start --force` option is fixed.  (LP: #869317)

Documentation
-------------
* Update the COPYING file to contain the GPLv3.  (LP: #790994)
* Major terminology change: ban the terms "queue runners" and "qrunners" since
  not all runners manage queue directories.  Just call them "runners".  Also,
  the master is now just called "the master runner".

Testing
-------
* New configuration variable in [devmode] section, called `wait` which sets
  the timeout value used in the test suite for starting up subprocesses.
* Handle SIGTERM in the REST server so that the test suite always shuts down
  correctly.  (LP: #770328)

Other bugs and changes
----------------------
* Moderating a message with Action.accept now sends the message. (LP: #827697)
* Fix AttributeError triggered by i18n call in autorespond_to_sender()
  (LP: #827060)
* Local timezone in X-Mailman-Approved-At caused test failure. (LP: #832404)
* InvalidEmailAddressError no longer repr()'s its value.
* Rewrote a test for compatibility between Python 2.6 and 2.7. (LP: #833208)
* Fixed Postfix alias file generation when more than one mailing list
  exists.  (LP: #874929).  Given by Vincent Fretin.


3.0 alpha 7 -- "Mission"
========================
(2011-04-29)

Architecture
------------
* Significant updates to the subscription model.  Members can now subscribe
  with a preferred address, and changes to that will be immediately reflected
  in mailing list subscriptions.  Users who subscribe with an explicit
  address can easily change to a different address, as long as that address
  is verified.  (LP: #643949)
* IUsers and IMembers are now assigned a unique, random, immutable id.
* IUsers now have created_on and .preferred_address properties.
* IMembers now have a .user attribute for easy access to the subscribed user.
* When created with add_member(), passwords are always stored encrypted.
* In all interfaces, "email" refers to the textual email address while
  "address" refers to the `IAddress` object.
* mailman.chains.base.Chain no longer self registers.
* New member and nonmember moderation rules and chains.  This effectively
  ports moderation rules from Mailman 2 and replaces attributes such as
  member_moderation_action, default_member_moderation, and
  generic_nonmember_action.  Now, nonmembers exist as subscriptions on a
  mailing list and members have a moderation_action attribute which describes
  the disposition for postings from that address.
* Member.is_moderated was removed because of the above change.
* default_member_action and default_nonmember_action were added to mailing
  lists.
* All sender addresses are registered (unverified) with the user manager by
  the incoming queue runner.  This way, nonmember moderation rules will
  always have an IAddress that they can subscribe to the list (as
  MemberRole.nonmember).
* Support for SMTP AUTH added via smtp_user and smtp_pass configuration
  variables in the [mta] section.  (LP: #490044)
* IEmailValidator interface for pluggable validation of email addresses.
* .subscribe() is moved from the IAddress to the IMailingList
* IAddresses get their registered_on attribute set when the object is created.

Configuration
-------------
* [devmode] section gets a new 'testing' variable.
* Added password_scheme and password_length settings  for defining the
  default password encryption scheme.
* creator_pw_file and site_pw_file are removed.

Commands
--------
* 'bin/mailman start' does a better job of producing an error when Mailman is
  already running.
* 'bin/mailman status' added for providing command line status on the master
  queue runner watcher process.
* 'bin/mailman info' now prints the REST root url and credentials.
* mmsitepass removed; there is no more site password.

REST
----
* Add Basic Auth support for REST API security.  (Jimmy Bergman)
* Include the fqdn_listname and email address in the member JSON
  representation.
* Added reply_goes_to_list, send_welcome_msg, welcome_msg,
  default_member_moderation to the mailing list's writable attributes in the
  REST service.  (Jimmy Bergman)
* Expose the new membership model to the REST API.  Canonical member resource
  URLs are now much shorter and live in their own top-level namespace instead
  of within the mailing list's namespace.
* /addresses/<email>/memberships gets all the memberships for a given email
  address.
* /users is a new top-level URL under which user information can be
  accessed.  Posting to this creates new users.
* Users can subscribe to mailing lists through the REST API.
* Domains can be deleted via the REST API.
* PUT and PATCH to a list configuration now returns a 204 (No Content).

Build
-----
* Support Python 2.7. (LP: #667472)
* Disable site-packages in buildout.cfg because of LP: #659231.
* Don't include eggs/ or parts/ in the source tarball. (LP: #656946)
* flufl.lock is now required instead of locknix.

Bugs fixed
----------
* Typo in scan_message(). (LP: #645897)
* Typo in add_member().  (LP: #710182) (Florian Fuchs)
* Re-enable bounce detectors. (LP: #756943)
* Clean up many pyflakes problems; ditching pylint.


3.0 alpha 6 -- "Cut to the Chase"
=================================
(2010-09-20)

Commands
--------
* The functionality of 'bin/list_members' has been moved to
  'bin/mailman members'.
* 'bin/mailman info' -v/--verbose output displays the file system
  layout paths Mailman is currently configured to use.

Configuration
-------------
* You can now configure the paths Mailman uses for queue files, lock files,
  data files, etc. via the configuration file.  Define a file system 'layout'
  and then select that layout in the [mailman] section.  Default layouts
  include 'local' for putting everything in /var/tmp/mailman, 'dev' for local
  development, and 'fhs' for Filesystem Hierarchy Standard 2.3 (LP #490144).
* Queue file directories now live in $var_dir/queues.

REST
----
* lazr.restful has been replaced by restish as the REST publishing technology
  used by Mailman.
* New REST API for getting all the members of a roster for a specific mailing
  list.
* New REST API for getting and setting a mailing list's configuration.  GET
  and PUT are supported to retrieve the current configuration, and set all
  the list's writable attributes in one request.  PATCH is supported to
  partially update a mailing list's configuration.  Individual options can be
  set and retrieved by using subpaths.
* Subscribing an already subscribed member via REST now returns a 409 HTTP
  error.  LP: #552917
* Fixed a bug when deleting a list via the REST API.  LP: #601899

Architecture
------------
* X-BeenThere header is removed.
* Mailman no longer touches the Sender or Errors-To headers.
* Chain actions can now fire Zope events in their _process()
  implementations.
* Environment variable $MAILMAN_VAR_DIR can be used to control the var/
  directory for Mailman's runtime files.  New environment variable
  $MAILMAN_UNDER_MASTER_CONTROL is used instead of the qrunner's --subproc/-s
  option.

Miscellaneous
-------------
* Allow X-Approved and X-Approve headers, equivalent to Approved and
  Approve. LP: #557750
* Various test failure fixes.  LP: #543618, LP: #544477
* List-Post header is retained in MIME digest messages.  LP: #526143
* Importing from a Mailman 2.1.x list is partially supported.


3.0 alpha 5 -- "Distant Early Warning"
======================================
(2010-01-18)

REST
----
* Add REST API for subscription services.  You can now:

  - list all members in all mailing lists
  - subscribe (and possibly register) an address to a mailing list
  - unsubscribe an address from mailing list

Commands
--------
* 'bin/dumpdb' is now 'bin/mailman qfile'
* 'bin/unshunt' is now 'bin/mailman unshunt'
* Mailman now properly handles the '-join', '-leave', and '-confirm' email
  commands and sub-addresses.  '-subscribe' and '-unsubscribe' are aliases
  for '-join' and '-leave' respectively.

Configuration
-------------
* devmode settings now live in their own [devmode] section.
* Mailman now searches for a configuration file using this search order.  The
  first file that exists is used.

  - -C config command line argument
  - $MAILMAN_CONFIG_FILE environment variable
  - ./mailman.cfg
  - ~/.mailman.cfg
  - /etc/mailman.cfg


3.0 alpha 4 -- "Vital Signs"
============================
(2009-11-28)

Commands
--------
* 'bin/inject' is now 'bin/mailman inject', with some changes
* 'bin/mailmanctl' is now 'bin/mailman start|stop|reopen|restart'
* 'bin/mailman version' is added (output same as 'bin/mailman --version')
* 'bin/mailman members' command line arguments have changed.  It also
  now ignores blank lines and lines that start with #.  It also no longer
  quits when it sees an address that's already subscribed.
* 'bin/withlist' is now 'bin/mailman withlist', and its command line
  arguments have changed.
* 'bin/mailman lists' command line arguments have changed.
* 'bin/genaliases' is now 'bin/mailman aliases'

Architecture
------------
* A near complete rewrite of the low-level SMTP delivery machinery.  This
  greatly improves readability, testability, reuse and extensibility.  Almost
  all the old functionality has been retained.  The smtp_direct.py handler is
  gone.
* Refactor model objects into the mailman.model subpackage.
* Refactor most of the i18n infrastructure into a separate flufl.i18n package.
* Switch from setuptools to distribute.
* Remove the dependency on setuptools_bzr
* Do not create the .mo files during setup.

Configuration
-------------
* All log files now have a '.log' suffix by default.
* The substitution placeholders in the verp_format configuration variable
  have been renamed.
* Add a devmode configuration variable that changes some basic behavior.
  Most importantly, it allows you to set a low-level SMTP recipient for all
  mail for testing purposes.  See also devmode_recipient.


3.0 alpha 3 -- "Working Man"
============================
(2009-08-21)

Configuration
-------------
* Configuration is now done through lazr.config.  Defaults.py is
  dead.  lazr.config files are essentially hierarchical ini files.
* Domains are now stored in the database instead of in the configuration file.
* pre- and post- initialization hooks are now available to plugins.  Specify
  additional hooks to run in the configuration file.
* Add the environment variable $MAILMAN_CONFIG_FILE which overrides the -C
  command line option.
* Make LMTP more compliant with Postfix docs (Patrick Koetter)
* Added a NullMTA for mail servers like Exim which just work automatically.

Architecture
------------
* 'bin/mailman' is a new super-command for managing Mailman from the command
  line.  Some older bin scripts have been converted, with more to come.
* Mailman now has an administrative REST interface which can be used to get
  information from and manage Mailman remotely.
* Back port of Mailman 2.1's limit on .bak file restoration.  After 3
  restores, the file is moved to the bad queue, with a .psv extension. (Mark
  Sapiro)
* Digest creation is moved into a new queue runner so it doesn't block main
  message processing.

Other changes
-------------
* bin/make_instance is no longer necessary, and removed
* The debug log is turned up to info by default to reduce log file spam.

Building and installation
-------------------------
* All doc tests can now be turned into documentation, via Sphinx.  Just run
  bin/docs after bin/buildout.


3.0 alpha 2 -- "Grand Designs"
==============================
(03-Jan-2009)

Licensing
---------

* Mailman 3 is now licensed under the GPLv3.

Bug fixes
---------

* Changed bin/arch to attempt to open the mbox before wiping the old
  archive. Launchpad bug #280418.

* Added digest.mbox and pending.pck to the 'list' files checked by
  check_perms. Launchpad bug #284802.

Architecture
------------

* Converted to using zope.testing as the test infrastructure.  Use bin/test
  now to run the full test suite.
  <https://pypi.org/project/zope.testing/3.7.1/>
* Partially converted to using lazr.config as the new configuration
  regime.  Not everything has been converted yet, so some manual editing
  of mailman/Defaults.py is required.  This will be rectified in future
  versions.  <https://launchpad.net/lazr.config>
* All web-related stuff is moved to its own directory, effectively moving
  it out of the way for now.
* The email command infrastructure has been reworked to play more nicely
  with the plug-in architecture.  Not all commands have yet been
  converted.

Other changes
-------------

* The LMTP server now properly calculates the message's original size.
* For command line scripts, -C names the configuration file to use.  For
  convenient testing, if -C is not given, then the environment variable
  MAILMAN_CONFIG_FILE is consulted.
* Support added for a local MHonArc archiver, as well as archiving
  automatically in the remote Mail-Archive.com service.
* The permalink proposal for supporting RFC 5064 has been adopted.
* Mailing lists no longer have a .web_page_url attribute; this is taken from
  the mailing list's domain's base_url attribute.
* Incoming MTA selection is now taken from the config file instead of
  plugins.  An MTA for Postfix+LMTP is added.  bin/genaliases works again.
* If a message has no Message-ID, the stock archivers will return None for
  the permalink now instead of raising an assertion.
* IArchiver no longer has an is_enabled property; this is taken from the
  configuration file now.

Installation
------------

* Python 2.6 is the minimal requirement.
* Converted to using zc.buildout as the build infrastructure.  See
  docs/ALPHA.txt for details.
  <https://pypi.org/project/zc.buildout/1.1.1/>


3.0 alpha 1 -- "Leave That Thing Alone"
=======================================
(08-Apr-2008)

User visible changes
--------------------

* So called 'new style' subject prefixing is the default now, and the only
  option.  When a list's subject prefix is added, it's always done so before
  any Re: tag, not after.  E.g. '[My List] Re: The subject'.
* RFC 2369 headers List-Subscribe and List-Unsubscribe now use the preferred
  -join and -leave addresses instead of the -request address with a subject
  value.

Configuration
-------------

* There is no more separate configure; make; make install step. Mailman 3.0
  is a setuptools package.
* Mailman can now be configured via a 'mailman.cfg' file which lives in
  $VAR_PREFIX/etc.  This is used to separate the configuration from the
  source directory.  Alternative configuration files can be specified via
  -C/--config for most command line scripts.  mailman.cfg contains Python
  code.  mm_cfg.py is no more.  You do not need to import Defaults.py in
  etc/mailman.cfg.  You should still consult Defaults.py for the list of site
  configuration variables available to you.

  See the etc/mailman.cfg.sample file.
* PUBLIC_ARCHIVE_URL and DEFAULT_SUBJECT_PREFIX now takes $-string
  substitutions instead of %-string substitutions.  See documentation in
  Defaults.py.in for details.
* Message headers and footers now only accept $-string substitutions;
  %-strings are no longer supported.  The substitution variable
  '_internal_name' has been removed; use $list_name or $real_name
  instead.  The substitution variable $fqdn_listname has been added.
  DEFAULT_MSG_FOOTER in Defaults.py.in has been updated accordingly.
* The KNOWN_SPAMMERS global variable is replaced with HEADER_MATCHES.  The
  mailing list's header_filter_rules variable is replaced with header_matches
  which has the same semantics as HEADER_MATCHES, but is list-specific.
* DEFAULT_MAIL_COMMANDS_MAX_LINES -> EMAIL_COMMANDS_MAX_LINES
* All SMTP_LOG_* templates use $-strings and all consistently write the
  Message-ID as the first item in the log entry.
* DELIVERY_MODULE now names a handler, not a module (yes, this is a
  misnomer, but it will likely change again before the final release).

Architecture
------------

* Internally, all strings are Unicodes.
* Implementation of a chain-of-rules based approach for deciding whether a
  message should initially be accepted, held for approval, rejected/bounced,
  or discarded.  This replaces most of the disposition handlers in the
  pipeline.  The IncomingRunner now only processes message through the rule
  chains, and once accepted, places the message in a new queue processed by
  the PipelineRunner.
* Substantially reworked the entire queue runner process management,
  including mailmanctl, a new master script, and the qrunners.  This should
  be much more robust and reliable now.
* The Storm ORM is used for data storage, with the SQLite backend as the
  default relational database.
* Zope interfaces are used to describe the major components.
* Users are now stored in a unified database, and shared across all mailing
  lists.
* Mailman's web interface is now WSGI compliant.  WSGI is a Python standard
  (PEP 333) allowing web applications to be (more) easily integrated with any
  number of existing Python web application frameworks.  For more information
  see:

  https://wsgi.readthedocs.io/en/latest/
  https://www.python.org/dev/peps/pep-0333/

  Mailman can still be run as a traditional CGI program of course.
* Mailman now provides an LMTP server for more efficient integration with
  supporting mail servers (e.g. Postfix, Sendmail).  The Local Mail Transport
  Protocol is defined in RFC 2033:

  http://www.faqs.org/rfcs/rfc2033.html
* Virtual domains are now fully supported in that mailing lists of the same
  name can exist in more than one domain.  This is accomplished by renaming
  the lists/ and archives/ subdirectories after the list's posting address.
  For example, data for list foo in example.com and list foo in example.org
  will be stored in lists/foo@example.com and lists/foo@example.org.

  For Postfix or manual MTA users, you will need to regenerate your mail
  aliases.  Use bin/genaliases.

  VIRTUAL_HOST_OVERVIEW has been removed, effectively Mailman now operates
  as if it were always enabled.  If your site has more than one domain,
  you must configure all domains by using add_domain() in your
  etc/mailman.cfg flie (see below -- add_virtual() has been removed).
* If you had customizations based on Site.py, you will need to re-implement
  them.  Site.py has been removed.
* The site list is no more.  You can remove your 'mailman' site list unless
  you want to retain it for other purposes, but it is no longer used (or
  required) by Mailman.  You should set NO_REPLY_ADDRESS to an address that
  throws away replies, and you should set SITE_OWNER_ADDRESS to an email
  address that reaches the person ultimately responsible for the Mailman
  installation.  The MAILMAN_SITE_LIST variable has been removed.
* qrunners no longer restart on SIGINT; SIGUSR1 is used for that now.

Internationalization Big Changes
--------------------------------

* Translators should work only on messages/<lang>/LC_MESSAGES/mailman.po.
  Templates files are generated from mailman.po during the build process.

New Features
------------

* Confirmed member change of address is logged in the 'subscribe' log, and if
  admin_notify_mchanges is true, a notice is sent to the list owner using a
  new adminaddrchgack.txt template.
* There is a new list attribute 'subscribe_auto_approval' which is a list of
  email addresses and regular expressions matching email addresses whose
  subscriptions are exempt from admin approval. RFE 403066.

Command line scripts
--------------------

* Most scripts have grown a -C/--config flag to allow you to specify a
  different configuration file.  Without this, the default etc/mailman.cfg
  file will be used.
* the -V/--virtual-host-overview switch in list_lists has been removed, while
  -d/--domain and -f/--full have been added.
* bin/newlist is renamed bin/create_list and bin/rmlist is renamed
  bin/remove_list.  Both take fully-qualified list names now (i.e. the list's
  posting address), but also accept short names, in which case the default
  domain is used.  newlist's -u/--urlhost and -e/--emailhost switches have
  been removed.  The domain that the list is being added to must already
  exist.
* Backport the ability to specify additional footer interpolation variables
  by the message metadata 'decoration-data' key.

Bug fixes and other patches
---------------------------

* Removal of DomainKey/DKIM signatures is now controlled by Defaults.py
  mm_cfg.py variable REMOVE_DKIM_HEADERS (default = No).
* Queue runner processing is improved to log and preserve for analysis in the
  shunt queue certain bad queue entries that were previously logged but lost.
  Also, entries are preserved when an attempt to shunt throws an exception
  (1656289).
* The processing of Topics regular expressions has changed. Previously the
  Topics regexp was compiled in verbose mode but not documented as such which
  caused some confusion.  Also, the documentation indicated that topic
  keywords could be entered one per line, but these entries were not handled
  properly.  Topics regexps are now compiled in non-verbose mode and multi-
  line entries are 'ored'.  Existing Topics regexps will be converted when
  the list is updated so they will continue to work.
* The List-Help, List-Subscribe, and List-Unsubscribe headers were
  incorrectly suppressed in messages that Mailman sends directly to users.
* The 'adminapproved' metadata key is renamed 'moderator_approved'.
