Hello,
Thanks a lot Noel for this bird's-eye view of possible solutions. The most promising tool for my setting seems to be Postfwd, which I'll now explore.
Sébastien.
One of the casualties in the war on spam is mail forwarders. The built-in postfix way to control the sender/recipient pairs is restriction classes. This works well for a small number of combinations, but quickly gets unmanageable. http://www.postfix.org/RESTRICTION_CLASS_README.html You can use a postfix policy service such as postfwd to create a list of allowed senders for some particular recipient. This isn't difficult, but will require manual intervention anytime a change is needed. Postfwd may be kinda old, but is still widely used. http://postfwd.org/ Another alternative is to use one of the existing perl (or java) milters such as milter-regex and add your sender/recipient checks there. Some ideas here, but just about any milter should work: http://www.postfix.org/addon.html Or just blow the whole thing up. Either host the mail locally and stop forwarding, or migrate your domain to gsuite so it's all inside their system. -- Noel Jones
