Re: Mailing list manager on NetBSD

[Silas <silas%nocafe.net@localhost>]

On Wed, Jan 16, 2019 at 07:09:56AM +0530, Mayuresh wrote:
> Since your friend runs multiple lists, may be he has been able to put such
> restriction. Please do share if you can.

I talked to him.  He let it be clear that it is a [ugly?] workaround.  
Actually, he wanted to use a mailing list manager, although he agreed 
that it might not free the server from the load that happens when 
someone (like the university administration) sends an email to 10000+ 
students.

In main.cf, he adds his own thing to smtpd_recipient_restrictions:

   smtpd_recipient_restrictions =
           permit_mynetworks,
           reject_non_fqdn_recipient,
           reject_unauth_pipelining,
           reject_unauth_destination,
           ... other things ...
           $myrestrictions

In the same file, there is:

   myrestrictions=check_policy_service unix:/var/run/myrestrictions/myrestrictions.sock

(Apparently, he could have configured "myrestrictions" in master.cf, but 
he did that in main.cf)

Now, in master.cf, for the submission service, he adds this:

   -o smtpd_recipient_restrictions=$myrestrictions,permit_sasl_authenticated,reject

All right, what opens the myrestrictions.sock socket?  A program he 
wrote (he wrote this in his favorite script language) that does the 
heavy work.  This script is started and daemonize at the server startup 
(there is a /etc/init.d [this is GNU/Linux] that run it).

This script does a lot of more things in spaghetti style.  It seemed 
that this Postfix server grew from a small one to a very big disorderly 
one with thousands of users.

I think, in general, it is something like that.