Commit Graph

122 Commits

Author SHA1 Message Date
Martin Weinelt 0da8e2b197 quota: expose global quota settings
With the options in the upstream dovecot module gone the quota support
and its option now live in our downstream module.

The only behavior change this introduces is not setting a global per
user default instead of the previous 100G per user.

Diabling quota support and setting per user quotas now raises an
assertion:

````
Failed assertions:
- Without quota support enabled, per-user quotas cannot be applied to the following accounts:

  - lowquota@example.com

  Either remove per user quota settings or re-enable `mailserver.quota.enable`.
````
2026-04-13 01:19:14 +02:00
Martin Weinelt e9337b346f Rename mailserver.loginAccounts to mailserver.accounts
The "login" prefix makes this option more confusing rather than clearer,
because what other account types are there? LDAP ones for example, but
you can login with those too, so the prefix is pointless.
2026-03-24 01:35:48 +01:00
Martin Weinelt 31c7607ef4 Rename extraVirtualAliases to aliases and update description
The extra and virtual parts are redundant and Postfix specific and not
at all required. Compare forwards for example.
2026-03-23 16:26:32 +01:00
Martin Weinelt 86d256870b postfix: prune virtual delivery agent settings
We exclusively rely on delivery via dovecot-lmtp, so these are redundant.
2026-03-23 13:23:01 +01:00
Martin Weinelt 63365fb1a8 postfix: document ldap map purposes 2026-03-21 01:38:04 +01:00
Martin Weinelt 762f553643 ldap: make uid the default account name
I fail to understand how mail became the uidAttribute way back when LDAP
support was introduced, but it was unintentional and clearly a mistake.

The uid attribute is the standard system login name per RFC4519 2.39 and
what we default to going forward.
2026-03-21 01:38:04 +01:00
Martin Weinelt a87d01ea79 ldap: reorganize and regroup options
Now that we have more experience with how we use the LDAP module options
we can make smarter decisions in how to organize them. We can also
explain much better what these options imply, which results in more
extensive option documentation.
2026-03-21 01:38:04 +01:00
lennart 5544b0fa70 Add rejectSenderMessage option 2026-03-20 10:16:09 +00:00
Martin Weinelt 6ff4a50f02 Add support for DKIM key management
After bumping the generation of new DKIM keys to RSA 2048 in NixOS 25.11
key rotation for existing users could not be done safely.

To resolve this situation we now support multiple generations of
selectors per domain to enable proper DKIM key transitions as described
in RFC6376 3.1. The added documentation introduces and motivates DKIM
and guides the user through a DKIM key rotation.

Additionally, DKIM key material can now also be treated as a managed
secrets when autogenerated state on the mail server host is undesirable.

This change is fully backwards compatible in behavior and will continue
to use the previously generated DKIM key without any additional
configuration up until the point when DKIM selectors are configured
explicitly.
2026-03-11 22:37:49 +01:00
Martin Weinelt 33ba1ff52b Switch to NixOS ACME module for certificate management
Drop most of the existing certificate handling, because we're effectively
duplicating functionality that NixOS offers for free with better
design, testing and maintainance than what we could provide downstream.

The remaining two options are to reference an
existing `security.acme.certs` configuration through
`mailserver.x509.useACMEHost` or to provide existing key material via
`mailserver.x509.certificateFile` and `mailserver.x509.privateKeyFile`.

Support for automatic creation of self-signed certificates has been
removed, because it is undesirable in public mail setups.

The updated setup guide now displays the recommended configuration that
relies on the NixOS ACME module, but requires further customization to
select a suitable challenge.

Co-Authored-By: Emily <git@emilylange.de>
2025-12-19 02:36:28 +01:00
Martin Weinelt eeda8ba39e Add support for sender rewriting using postsrsd
With SRS we support forwarding of mails without (fully) breaking SPF
alignment.
2025-11-11 13:45:03 +01:00
Martin Weinelt edb7b661e4 postfix: resolve main/master option deprecation 2025-11-10 02:56:51 +01:00
Martin Weinelt b99f353ab8 postfix: unquote tls_config_file value
This can now be a path type due to changes applied to nixos unstable.
2025-11-10 02:51:46 +01:00
Martin Weinelt a1532a552f postfix: enable X25519MLKEM768 key exchange
This migrates the key exchange curve group configuration into the OpenSSL
configuration format, which is the only path forward to configure these.

We now prefer a hybrid key exchange for TLS handshake and as a client
we'll send key shares for that and pure X25519, while keeping backwards-
compat for P256 and P384.

The statistics for my personal mail server over the last month show a
clear trend for X25519 key exchanges:

    156 secp384r1
    225 secp256r1
    19541 x25519
2025-11-10 00:31:43 +01:00
Martin Weinelt 3555a546ab Add support for SMTP TLS reports
When enabled the tlsrpt services will send out aggregated reports about
TLS connections the local Postfix made to interested parties, who set up
a `_smtp._tls` TXT record with a rua attribute.

Introduces mailserver.systemContact to specify an administrative contact
advertised in these automated reports.
2025-11-08 22:39:29 +01:00
Martin Weinelt 0812ca1e48 Use postfix-tlspol for DANE/MTA-STS policy lookups
Postfix with plain DANE only secures domains that configure DNSSEC and
publish TLSA records. With postfix-tlspol we support MTA-STS protected
connections and get caching for its policy results.

Finally, we use this as a stepping stone to build TLSRPT support on top.
2025-11-08 15:49:34 +01:00
Martin Weinelt b76a547bec treewide: reformat with nixfmt 1.0.0 2025-08-02 02:19:15 +02:00
Martin Weinelt 027e6bcd76 postfix: don't cast message_size_limit to string
On unstable this will become a signed integer and there was never a good
reason for this to be a string.
2025-08-02 02:11:11 +02:00
Martin Weinelt d6d2053b80 dovecot: use marker option as unit name migration indicator
In nixpkgs we expose `services.dovecot.hasNewUnitName` option that can be
safely inspected to understand that whether to use the `dovecot` systemd
service name instead of `dovecot2`.
2025-07-07 01:10:19 +02:00
Martin Weinelt 64aca4f2ce postfix: disable SHA1 for SMTP connections 2025-06-18 06:58:42 +02:00
Martin Weinelt 6652b57dda postfix: rearrange smtpd_tls_chain_files option 2025-06-16 07:27:03 +02:00
Martin Weinelt c8f809fa76 postfix: migrate more options to services.postfix.config
I'm working on deprecating the top-level options, that configure main.cf
upstream in nixpkgs. With this change we stay ahead of the curve.

The `networks_style` option already defaults to `host` since Postfix 3.0,
so I dropped the setting.

```
$ postconf -d | grep networks_style
mynetworks_style = ${{$compatibility_level} <level {2} ? {subnet} : {host}}
````
2025-06-16 07:03:49 +02:00
Martin Weinelt a2152f9807 treewide: remove overly broad with cfg
Makes it really hard to follow references and we were being explicit in
most places already anyway.
2025-06-15 05:39:20 +02:00
Martin Weinelt 1a7f3d718c treewide: reformat with nixfmt-rfc-style 2025-06-15 03:39:44 +02:00
Martin Weinelt c7497cd5f6 treewide: remove redundant parenthesis in nix code 2025-06-15 03:28:48 +02:00
Martin Weinelt 5f592b5960 Merge branch 'crypto-v2' into 'master'
postfix, dovecot: modernize and comment TLS settings

See merge request simple-nixos-mailserver/nixos-mailserver!413
2025-06-14 22:52:29 +00:00
Martin Weinelt 4fd9508d41 postfix: drop tls_random_source config
The setting already defaults to /dev/urandom.
2025-06-15 00:22:57 +02:00
Martin Weinelt 3828b00dea postfix: configure preferred curves and disable FFDHE
This aligns with the intermediate configuration recommended by Mozilla.
2025-06-15 00:22:57 +02:00
Martin Weinelt e27326d317 postfix: refactor and prune TLS settings
- Groups settings between server and client
- Uses a range comparator for supported TLS versions
- Prune excluded primitives to what affects the supported TLS versions
2025-06-15 00:22:57 +02:00
Martin Weinelt 23cc9a3996 Merge branch 'postfix-cert-key' into 'master'
postfix: configure cert/key using smtpd_tls_chain_files

Closes #183

See merge request simple-nixos-mailserver/nixos-mailserver!410
2025-06-14 12:47:58 +00:00
Martin Weinelt 3f1c6960d3 Merge branch 'smptp-smuggling-cleanup' into 'master'
postfix: remove option to toggle SMTP smuggling workarounnd

See merge request simple-nixos-mailserver/nixos-mailserver!411
2025-06-12 22:57:43 +00:00
Martin Weinelt f1bd4b8215 postfix: remove option to toggle SMTP smuggling workarounnd
It has been default enabled since Postfix 3.9 and can still be configured
from the NixOS option mentioned in the removal warning.

Removing the option makes our interface leaner.

Information is based on https://www.postfix.org/smtp-smuggling.html#long.
2025-06-13 00:21:16 +02:00
Martin Weinelt e540dc864c postfix: configure cert/key using smtpd_tls_chain_files
The sslCert and sslKey options are going away, because they do too much,
e.g. provision the keypair for client certificate authentication, which
is not at all what we want or need.
2025-06-12 01:05:51 +02:00
Martin Weinelt f9b15192b8 postfix: allow client to select the preferred cipher
As long as all cipher we support are considered safe we can allow clients
to select one that suits them best.
2025-06-03 00:45:12 +02:00
Martin Weinelt aa8366d234 treewide: remove dead nix references 2025-05-15 16:41:30 +02:00
Martin Weinelt a1ff289bf9 dovecot: migrate queue-status to UNIX domain socket 2025-05-07 18:00:53 +02:00
lewo 7bb0f43503 Merge branch 'dane-lookups' into 'master'
postfix: Support opportunistic DANE TLS

See merge request simple-nixos-mailserver/nixos-mailserver!389
2025-05-07 07:02:02 +00:00
Martin Weinelt 2e254b4b5e postfix: adjust comments around smtpd_recipient_restrictions 2025-05-07 02:52:28 +02:00
Martin Weinelt fac7efe946 postfix: Support opportunistic DANE TLS
This migrates the security level for outgoing SMTP connections to
dane[1]. Either a server is configured for DANE or it now uses mandatory
unauthenticated TLS.

If DANE validation fails, the delivery will be tempfailed.

If DANE is invalid or unusable the connection will fall back to
unauthenticated mandatory TLS

This has been the default in various mail distributions:
- Mailcow since December 2016[2]
- mailinabox since July 2014[3]

[1] https://www.postfix.org/TLS_README.html#client_tls_dane
[2] https://github.com/mailcow/mailcow-dockerized/commit/47a5166383a4ecae780ffd6ad2081dc3f070bd45
[3] https://github.com/mail-in-a-box/mailinabox/commit/e713af5f5aeca202c2bf88be324472b3ef898dc7
2025-05-07 02:23:32 +02:00
Robert Schütz 71c5fe04f1 postfix: disable TLSv1.1
In accordance with https://ssl-config.mozilla.org/#server=postfix.
2025-05-06 02:42:13 -07:00
Martin Weinelt 630b5c4fdd Use rspamd for DKIM signing, drop OpenDKIM
OpenDKIM has not been updated in the last 7 years and failed to adopt
RFC8463, which introduces Ed25519-SHA256 signatures.

It has thereby held back the DKIM ecosystem, which relies on the DNS
system to publish its public keys. The DNS system in turn does not handle
large record sizes well (see RFC8301), which is why Ed25519 public keys
would be preferable, but I'm not sure the ecosystem has caught up, so we
stay on the conservative side with RSA for now.

Fixes: #203 #210 #279
Obsoletes: !162 !338
Supersedes: !246
2025-05-06 01:05:10 +02:00
Sandro Jäckel bba070a1fe Remove policy-spf
Rspamd can do the same as policy-spf, only better, with more settings, is well integrated and better maintained.
Other projects are going the same route [1].

[1]: https://docker-mailserver.github.io/docker-mailserver/latest/config/best-practices/dkim_dmarc_spf/
2025-04-17 20:26:00 +02:00
Philipp Bartsch 9b5df96132 postfix: enable smtp tls logging
Log a summary message on TLS handshake completion.
2025-03-19 19:12:49 +00:00
Isabel 290a995de5 refactor: policyd-spf -> spf-engine 2024-06-18 09:03:27 +01:00
Martin Weinelt ed80b589d3 postfix: remove deprecated smtpd_tls_eecdh_grade
Causes a warning that suggests to just leave it at its default.
2024-06-03 12:34:43 +02:00
Antoine Eiche b5023b36a1 postfix: exclude $mynetwork from smtpd_forbid_bare_newline 2023-12-27 09:46:26 +01:00
Alvar Penning 3f526c08e8 postfix: SMTP Smuggling Protection
Enable Postfix SMTP Smuggling protection, introduced in Postfix 3.8.4,
which is, currently, only available within the nixpkgs' master branch.

- https://github.com/NixOS/nixpkgs/pull/276104
- https://github.com/NixOS/nixpkgs/pull/276264

For information about SMTP Smuggling:

- https://www.postfix.org/smtp-smuggling.html
- https://www.postfix.org/postconf.5.html#smtpd_forbid_bare_newline
2023-12-23 20:15:16 +01:00
Jean-Baptiste Giraudeau 93221e4b25 Add support for regex (PCRE) aliases. 2023-09-05 14:58:10 +02:00
Antoine Eiche fb3210b932 ldap: do not write password to the Nix store 2023-07-11 19:31:20 +00:00
Antoine Eiche 33554e57ce Make the ldap test working
- The smtp/imap user name is now user@domain.tld
- Make the test_lookup function much more robust: it was now getting
  the correct file from the store.
2023-07-11 19:31:20 +00:00