Hello, I see a lot of spam entering that claims to have come from a local domain, usually guessing a non-existent account. I've been looking for a way to "reject_unverified_local_sender", by which I mean that the sender address is verified iff it occurs in virtual_alias_domains (and perhaps a few other lists).
One way to go could be to create a database of sender domains to validate, enter my own domains in it, and use "external" access to my own MTA and probing it. But that leads to cyclic probing! I suppose I am really looking for something simpler -- namely an invocation of the virtual(8) server for addresses on the said lists. I don't see how I can do this with Postfix, and it's not even simple in a policy due to the cyclic risk. What are others doing in this respect? Thanks, -Rick
