Mail/Postfix add LMTP feature request

[TosoBoso]

I really like the Mail/Postfix plugin and would love to use it with LMTP (local mail transport protocol) instead of SMTP.
I'm using Kopano as mail backend with LMTP:2003 as default way via virtual_mailbox_domains, virtual_transport = lmtp:IP:2003 or transport = lmtp:IP:2003.

To add LMTP should work straightforward and I tested it by adjusting the transport file, running postmap and restarting postfix without touching the GUI.
So on GUI level Domains if you would add the destination Protocol option to choose between SMTP vs. LMTP and for LMTP use Port 2003 as default the feature would be delivered.

Regards TosoBoso
PS: Proposed change snippets for lmtp feature (I'm not yet deep and brave enough for pull request):

• plugins/mail/postfix/src/opnsense/service/templates/OPNsense/Postfix/transport to change
  5: {{ domain.domainname }} domain.protocol:{{ domain.destination }}

• plugins/mail/postfix/src/opnsense/mvc/app/controllers/OPNsense/Postfix/forms/dialogEditPostfixDomain.xml to add
  20: (before )
  
  domain.protocol
  Protocol
  text
  Set the relay type protocol: default is smtp but also lmtp (local mail transport protocol) is supported e.g. using port :2003.
  

• plugins/mail/postfix/src/opnsense/mvc/app/controllers/OPNsense/Postfix/Api/DomainController.php replace
  41: return $this->searchBase('domains.domain', array("enabled", "domainname", "destination", "protocol"));

• plugins/mail/postfix/src/opnsense/mvc/app/models/OPNsense/Postfix/Domain.xml to add
  22: (before )
  
  smtp
  Y
  /^([l,s])mtp$/u
  Only smtp or lmtp are allowed
  

plugins/mail/postfix/src/opnsense/mvc/app/views/OPNsense/Postfix/domain.volt to add
62: (before <th data-column-id="uuid"..)
{{ lang._('Protocol') }}

[mimugmail]

What is the benefit of using lmtp compared to smtp?

[TosoBoso]

There is no benefit per se in LMTP just a native feature by Postfix also relaying to it which I'd like to use. SMTP is MDA (mail delivery agent) with queuing, spam etc. LMTP is lighweight mait transfer agent (MTA) for local transfer with no queuing etc. This is exactly the concept / use case: OPNsense with Postfix as mail-gateway on the wan delivering to internal mail system e.g. Kopano (ex Zarafa) which uses LMTP as default. At the moment I'm running Postfix (SMTP) in front of Kopano both in in containers connected via LMTP. With this LMTP feature I could skip my 2nd Postfix server by less is more principle. -Hope that clarifies.
-TosoBoso

[mimugmail]

Ok, thanks for the clarification. I don't know when I find the time for it, can't promise it will be there in the next 2 months.

[TosoBoso]

THX!

[ToKaDe]

I would like to use the Postfix plugin on opnsense, but in my current installation I use dovecot which uses LMTP as default.
So is there any development ongoing to implement LMTP as further protocol?

Thx and kind regards
Torsten

[mimugmail]

No, just install postfix on your dovecot instance

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