hello,
on our mx01 and mx02 we validate recipient adresses with
'reject_unverified_recipient'.
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 <p...@domainn.tld>: 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-bou...@mxdomain.tld>
to=<p...@domainn.tld> proto=ESMTP helo=<mx01.domainn.tld>
seems okay.
but the mx01 or mx02 says to sender:
450-4.1.1 <p...@domainn.tld>: Recipient address rejected: unverified
address: Address lookup failed.
so sender server will try and try and try again.
why is the mx01/mx02 answering with 4xx code, the destination said 5xx
code recipient unknown?
thank you for any help
marko
