Ryan Britton writes:
I just recently installed courier on my server and configured it. I
have four domains pointing to that server, all of which are listed
under the hosted domains. Three of these work perfectly fine for all
aspects of email. The fourth does not. Everything works fine except
for incoming mail, which always results in a 55x error code no matter
the address specified by the RCPT TO:<>.
MX records are identical across all domains. The only things unique
about the one that doesn't work is that the box happens to be one of
its DNS servers and the hostname of the box is the domain.
The recipient's domain is checked against the list of local domains, and
then the hosted domains. See the courier(8) man page for a description of
the key difference between a "local" and a "hosted" domain.
If you do not initialize the locals file, its default is the same as the
machine's hostname. As such, addresses with this domain are incorrectly
processed as local addresses, so the mailbox lookup fails.
You need to manually initialize the 'me' file to something other than the
machine's hostname, so that this domain is not recognized as a local domain,
but as a hosted domain.