Axel Luttgens: > 550 5.1.1 <j...@example.com>: Recipient address rejected: User unknown > in virtual mailbox table > > On the other hand, typing: > > rcpt to:<ab...@example.com> > > allows to go ahead and the message will be queued, then bounced > because the LMTP service ultimately rejects the target address > <j...@example.com>. > > So, a typo in both cases, but with two very different outcomes. > > Does this reflect what is meant by: > > An address is always considered "known" when it matches a > virtual(5) alias or a canonical(5) mapping.
Yes. Note that the resulting address may be remote, or it may resolve to a local alias that expands into a non-existent address. If you want immediate verification, use reject_unverified_recipient. This does a lot of work behind the scenes and then caches the result. http://www.postfix.org/ADDRESS_VERIFICATION_README.html#recipient Having Postfix do full address resolution for every RCPT TO command would make Postfix more vulnerable to denial-of-service attacks, because sending RCPT TO is much cheaper than recursively resolving multiple levels of address rewriting or aliasing that happens in a bunch of different processes from cleanup(8), trivial-rewrite(8), to local(8), virtual(8), lmtp(8) and so on. Wietse
