simple-nixos-mailserver/docs/release-notes.rst

Release Notes
=============

NixOS 26.05
-----------

- Certificate handling was simplified.  We recommend setting
  :option:`mailserver.x509.useACMEHost` to a ``security.acme.certs``
  configuration. If that does not fit your requirements, configure certificate
  and private key using :option:`mailserver.x509.certificateFile` and
  :option:`mailserver.x509.privateKeyFile` instead. Support for automatic
  creation of self-signed certificates has been removed.
  Check the updated `setup guide`_ for a basic ACME HTTP-01 example.
- `DKIM key management`_ is now available with multiple concurrent selectors per
  domain enabling proper DKIM key rotation. While we still generate a default
  key for backwards compatibility we now also support passing pre-created
  key material. If your DKIM keys were automatically created before the 25.11
  release they are 1024 bit RSA keys and should be rotated out.
  See :option:`mailserver.dkim.domains` for further relevant options.
- Cleartext password files can now be configured for login accounts. This
  is an alternative to hashed passwords that integrates well with workflows
  established by `agenix`_/`sops-nix`_ that instead rely on encryption. This
  option prevents files from leaking in to the Nix store.
  See :option:`mailserver.accounts.<name>.passwordFile`.
- TLS configurations have been updated:

  - TLSv1.2 cipher suites in Postfix now require `AEAD`_ and `ECDHE`_.
  - Postfix and Dovecot allow for the ``SecP256r1MLKEM768``
    key exchange, as specified in the ongoing
    `standardization effort <https://datatracker.ietf.org/doc/draft-ietf-tls-ecdhe-mlkem/>`__.
  - Postfix no longer supports uncommon, deprecated, and obsolete TLS signature
    algorithms.

- LDAP setups require a migration of Dovecot home directories to
  `UUID based home directories`_. The exact UUID attribute can be customized
  through :option:`mailserver.ldap.attributes.uuid`.
- The default login username for LDAP users has changed from the ``mail`` to
  the ``uid`` attribute. This allows users to login with their account name
  rather than their email address, which is more convenient and consistent
  with typical LDAP practices. The exact attribute can be customized through
  :option:`mailserver.ldap.attributes.username`.
- Local and LDAP accounts can now co-exist. For overlapping names and addresses
  the local account will always win.
- Custom reject messages for blocked senders are now possible by setting
  :option:`mailserver.rejectSenderMessage` to e.g. comply with GDPR.
- The following integrations are deprecated and will be removed before the next
  release:

  - :option:`mailserver.borgbackup.enable`
  - :option:`mailserver.backup.enable`
  - :option:`mailserver.monitoring.enable`

.. _setup guide: setup-guide.html#setup-the-server
.. _DKIM key management: dkim.html
.. _agenix: https://github.com/ryantm/agenix
.. _sops-nix: https://github.com/Mic92/sops-nix
.. _AEAD: https://en.wikipedia.org/wiki/Authenticated_encryption
.. _ECDHE: https://www.rfc-editor.org/rfc/rfc8422
.. _UUID based home directories: migrations.html#dovecot-ldap-uuid-based-home-directories

NixOS 25.11
-----------

- The ``systemName`` and ``systemDomain`` options have been introduced to have
  reusable configurations for automated reports (DMARC, TLSRPT). They come with
  reasonable defaults, but it is suggested to check and change them as needed.
- Support for the `Sender Rewriting Scheme`_ has been added, which allows
  forwarding mail without breaking SPF by rewriting the envelope address.
- The default key length for new DKIM RSA keys was increased to 2048 bits as
  recommended in `RFC 8301 3.2`_.
  We recommend rotating existing keys, as the RFC advises that signatures from
  1024 bit keys should not be considered valid any longer.
- IMAP access over port ``143/tcp`` is now default disabled in line
  with `RFC 8314 4.1`_. Use IMAP over implicit TLS on port ``993/tcp``
  instead. If you still require this feature you can re-enable it using
  ``mailserver.enableImap``, but it is scheduled for removal after the 25.11
  release.
- SMTP server and client now support and prefer a hybrid key exchange
  (X25519MLKEM768)
- SMTP access over STARTTLS on port ``587/tcp`` is now default disabled in line
  with `RFC 8314 3.3`_. If you still require this feature you can re-enable it
  using ``mailserver.enableSubmission``.
- DMARC reports are now sent with the ``noreply-dmarc`` localpart from the
  system domain.
- DANE and MTA-STS are now validated for outgoing SMTP connections using
  `postfix-tlspol`_.
- SMTP TLS connection reports (`RFC 8460`_) are now supported using
  `tlsrpt-reporter`_. They can be enabled with the ``mailserver.tlsrpt.enable``
  option.

.. _Sender Rewriting Scheme: srs.html
.. _RFC 8301 3.2: https://www.rfc-editor.org/rfc/rfc8301#section-3.2
.. _RFC 8314 3.3: https://www.rfc-editor.org/rfc/rfc8314#section-3.3
.. _RFC 8314 4.1: https://www.rfc-editor.org/rfc/rfc8314#section-4.1
.. _RFC 8460: https://www.rfc-editor.org/rfc/rfc8460
.. _postfix-tlspol: https://github.com/Zuplu/postfix-tlspol
.. _tlsrpt-reporter: https://github.com/sys4/tlsrpt-reporter

NixOS 25.05
-----------

- OpenDKIM has been removed and DKIM signing is now handled by Rspamd, which only supports ``relaxed`` canoncalizaliaton.
  (`merge request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/374>`__)
- Rspamd now connects to Redis over its Unix Domain Socket by default
  (`merge request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/375>`__)

  - If you need to revert TCP connections, configure ``mailserver.redis.address`` to reference the value of ``config.services.redis.servers.rspamd.bind``.
- The integration with policyd-spf was removed and SPF handling is now fully based on Rspamd scoring.
  (`merge request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/380>`__)
- Switch to the more efficient `fts-flatcurve` indexer for full text search
  (`merge request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/361>`__).

  This makes use of a new index, which will be automatically re-generated the
  next time a folder is searched.
  The operation is now quick enough to be performed "just-in-time".
  Alternatively, all indices can be immediately re-generated for all users and
  folders by running

  .. code-block:: bash

    doveadm fts rescan -u '*' && doveadm index -u '*' -q '*'

  The previous index (which is not automatically discarded to allow rollbacks)
  can be cleaned up by removing all the `xapian-indexes` directories within
  ``mailserver.indexDir``.
- Individual domains can now be excluded from DMARC Reporting through ``mailserver.dmarcReporting.excludedDomains``.
  (`merge request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/297>`__)
- Configuring ``mailserver.forwards`` is now possible when the setup relies on LDAP.
  (`merge request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/313>`__)
- Support for TLS 1.1 was disabled in accordance with `Mozilla's recommendations <https://ssl-config.mozilla.org/#server=postfix>`_.
  (`merge request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/234>`__)

NixOS 24.11
-----------

- No new feature, only bug fixes and documentation improvements

NixOS 24.05
-----------

- Add new option ``acmeCertificateName`` which can be used to support
  wildcard certificates

NixOS 23.11
-----------

- Add basic support for LDAP users
- Add support for regex (PCRE) aliases

NixOS 23.05
-----------

- Existing ACME certificates can be reused without configuring NGINX
- Certificate scheme is no longer a number, but a meaningful string instead

NixOS 22.11
-----------

- Allow Rspamd to send DMARC reporting
  (`merge request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/244>`__)

NixOS 22.05
-----------

- Make NixOS Mailserver options discoverable from search.nixos.org
- Add a roundcube setup guide in the documentation

NixOS 21.11
-----------

- Switch default DKIM body policy from simple to relaxed
  (`merge request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/247>`__)
- Ensure locally-delivered mails have the X-Original-To header
  (`merge request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/243>`__)
- NixOS Mailserver options are detailed in the `documentation
  <https://nixos-mailserver.readthedocs.io/en/latest/options.html>`__
- New options ``dkimBodyCanonicalization`` and
  ``dkimHeaderCanonicalization``
- New option ``certificateDomains`` to generate certificate for
  additional domains (such as ``imap.example.com``)

NixOS 21.05
-----------

- New `fullTextSearch` option to search in messages (based on Xapian)
  (`Merge Request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/212>`__)
- Flake support
  (`Merge Request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/200>`__)
- New `openFirewall` option defaulting to `true`
- We moved from Freenode to Libera Chat

NixOS 20.09
-----------

- IMAP and Submission with TLS wrapped-mode are now enabled by default
  on ports 993 and 465 respectively
- OpenDKIM is now sandboxed with Systemd
- New `forwards` option to forwards emails to external addresses
  (`Merge Request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/193>`__)
- New `sendingFqdn` option to specify the fqdn of the machine sending
  email (`Merge Request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/187>`__)
- Move the Gitlab wiki to `ReadTheDocs
  <https://nixos-mailserver.readthedocs.io/en/latest/>`_