[Mailman-Developers] Moderation rules priority

[Ian Eiloart]

On 18 Mar 2014, at 19:12, Barry Warsaw <barry at list.org> wrote:

> I see this was a private reply.  Feel free to forward this on to the list if
> you want.

Thanks, Barry. I’ll have a go at that if I get time. 

For me, the big win for spam prevention with mailing lists is the restriction on posters: it’s what keeps mailing lists relatively spam free. Most sites don’t like to bounce messages that they’ve previously accepted, so that means that the spam gets held for moderation, which creates a lot of work for list owners. If list bound mail can be rejected by the MTA at SMTP time, that would save a lot of work for list owners.

> On Mar 18, 2014, at 02:58 PM, Ian Eiloart wrote:
> 
>> That page suggests that Mailman 3 won’t be able to reject, at LMTP time, a
>> message based on the sender/recipient information. That means that the MTA
>> has to accept a message for delivery, even if Mailman is then going to reject
>> it because the sender isn’t permitted to post to the list, or even just
>> because the list doesn’t exist. Is that the case?
> 
> At the moment, yes, but if you're interested in working on this, here's a
> rough sketch that might work:
> 
> Amend LMTPRunner.process_message() to run the member-moderation and
> nonmember-moderation rules.  Probably rather than hard coding this, create a
> short chain just for LMTP-acceptance processing.  This would allow folks to
> customize what criteria the LMTP server uses to decide whether to accept the
> message or not.
> 
> .process_message() knows the name of the mailing list the message is destined
> for (via recipient inspection).  It currently doesn't query the db for a
> mailing list object because it doesn't need it, but that would be easy to add.
> You've already got the message object, so just craft an empty metadata
> dictionary for the chain processing.
> 
> Probably make the link action for both rules LinkAction.stop so that the first
> one to hit wins.  Then check the moderation_action to decide what the
> disposition should be.  E.g. if Action.reject or Action.discard, you can issue
> the appropriate LMTP response code.  If it's Action.hold, Action.accept, or
> Action.defer, accept the message at LMTP time and enqueue the message for full
> processing.
> 
> Cheers,
> -Barry

-- 
Ian Eiloart
Postmaster, University of Sussex
+44 (0) 1273 87-3148