Postfix header_check and deffered queue

Question

I know how to use header_check... but it works only on upcoming emails. I have to analyze the header again after the email is deferred and send it through different transport. The transport should be a script that analyze the content of the email and updates database with some information.

Any idea what I can use in postfix to create such a behavioral.

Answer 1

The way I would approach that is to use an smtp_fallback_relay to handle delivery of the deferred messages. You'll have to setup a 2nd postfix server or instance for the fallback relay, but it can have it's own set of checks that are independent of the primary.