[Mailman-Developers] Mailman and Submission port

[Stefan Förster]

* Patrick Ben Koetter <p at state-of-mind.de>:
> From my daily work with mailman the following "modified in some way"-tasks
> come to my mind immediately:
> 
> - apply client and content policy that differs from the port 25 anti-spam
>   policy
> - add DKIM signatures because it is clear mailman messages are ORIGINATING
>   from our network

I seem to remember a certain training where the two of us were showing
some very different ways on how to deal with individual policies ;-)

I don't think changing the default port would be such a great idea.
The submission port is widely used for messages submitted by _end
users_ - with all the necessary precautions in place, i.e. DNS checks,
SMTP AUTH and content filtering (at least virus filtering).

MM generated messages don't need DNS or virus checks - the messages
were already scanned when they entered the system, and temporary
rejects on DNS errors are detrimental to MM's bounce recognizing
abilities. There's a high probability you'd have to create a SMTP
listener with a dedicated policy set anyways - changing SMTPPORT in
mm_cfg.py is only a very minor task in setting up a mailing list
server.


Cheers
Stefan