Re: Mailing list manager on NetBSD

[Mayuresh <mayuresh%acm.org@localhost>]

On Thu, Jan 17, 2019 at 11:50:44AM -0200, Silas wrote:
> 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.

Thanks, and please convey my thanks to your friend for sharing this!

I was tinkering with this idea and came up with my version of ugliness.
While I have used postfix to set up simple mail server, I do not have much
experience of setting up the kind of things I illustrate below. The
documentation is really intimidating and semantics not easy to grasp.

This is adopted from /usr/share/examples/postfix/RESTRICTION_CLASS_README

main.cf:

# `permit' is really my trial and error outcome, most examples show
# "reject" there, but that leads to rejection of mails sent to non-list
# ids
smtpd_recipient_restrictions =
        ... other things...
        check_recipient_access hash:/etc/postfix/protected_destinations
        permit
insiders_only = check_sender_access hash:/etc/postfix/insiders
smtpd_restriction_classes = insiders_only

protected_destinations:

<list email id> insiders_only

insiders (generatable from the alias list):

<member addr 1> OK
<member addr 2> OK
...


This is kind of working for me, except that when a non-member's email gets
rejected, e.g. from  gmail, gmail shows "the remote server is
misconfigured". The status code is 554 5.7.1, which as per [1] looks ok
for the scenario.

Firstly why should gmail call it misconfigured, but the bigger worry is it
might blacklist the server if this happens too many times!

Looking for help on this.

Mayuresh


[1] https://tools.ietf.org/html/rfc3463