I am using postfix 3.1.4 on NetBSD 8. I am trying the idea of setting up a mailing list for a fairly static group of size not exceeding around 300, with postfix. I am doing this on a VPS server and want a solution that is conservative on resource footprint, hence considering doing it with MTA itself. [Please do comment whether postfix is suitable for this purpose.]
I am able to get the basic aliases functionality, Reply-To header modification etc. working fine. I just need a recipe to restrict senders to the members of the mailing list - only for the protected email id which is the list email id. The search led me to the following write up in /usr/share/examples/postfix/RESTRICTION_CLASS_README: In the general case you need two lookup tables: one table that lists destinations that need to be protected, and one table that lists domains that are allowed to send to the protected destinations. /etc/postfix/main.cf: smtpd_recipient_restrictions = ... check_recipient_access hash:/etc/postfix/protected_destinations ...the usual stuff... smtpd_restriction_classes = insiders_only insiders_only = check_sender_access hash:/etc/postfix/insiders, reject /etc/postfix/protected_destinations: all@my.domain insiders_only all@my.hostname insiders_only /etc/postfix/insiders: my.domain OK matches my.domain and subdomains another.domain OK matches another.domain and subdomains I am unable to follow this example, particularly due to the ellipsis part. Would appreciate if someone could elaborate this a bit further. Mayuresh