> on our mx01 and mx02 we validate recipient adresses with
> now i one case, the mx01 or mx02 connects on the destination machine
> and tries to validate the recipient.
> the result is:
> 550 5.1.1 <post@...>: Recipient address rejected: undeliverable
> address: host 192.168.50.1[192.168.50.1] said: 550 5.1.1 User unknown
> (in reply to RCPT TO command); from=<double-bounce@...>
> to=<post@...> proto=ESMTP helo=<mx01.domainn.tld>
> seems okay.
> but the mx01 or mx02 says to sender:
> 450-4.1.1 <post@...>: Recipient address rejected: unverified
> address: Address lookup failed.
If in doubt, read the documentation, CAREFULLY.