Chris St Denis wrote:
I need to add support for (multi-recipient) aliases that are only able
to receive messages from selected users.
I was initially looking at mailman or majordomo, however from what I
understand of them, they authenticate only on the from address so it
looks like it would be easy to forge. (Correct me if this is wrong).
There is no way to prevent strangers from forging straner identities.
this is not specific to email (If I call you on the phone, I can say
that I am foo bar, provided you don't know foo bar enough to detect the
forgery).
you can enforce authentication for _your_ users. you can also refuse
mail from external servers with a sender in your domain.
so go for a mailing list manager.
I also thought of smtpd_restriction_classes however that is also subject
to easy spoofing and the documentation even says "Postfix restriction
classes aren't really the right solution"
There is no way to prevent forgery. all you can do is make it harder by
requiring a login:password. but even this only reduces risks.
So I am wondering. What IS a good way to do this. Optimally, I would
like to restrict based on the SASL username.
enforce login and sender match. then restrict based on sender.
