Just this morning one of our users complained, that he couldn't send email
to a certain email address. When I looked into it, I found out the
following things:
bcr.ro preference = 10, mail exchanger = 194.102.94.1
bcr.ro preference = 10, mail exchanger = w\032\149\008
[root@mroute01 /root]# /opt/exim/bin/exim -bt XXX@???
mierat@??? is undeliverable:
all relevant MX records point to non-existent hosts: it appears that the
DNS operator for this domain has
installed an invalid MX record with an IP address instead of a domain name
on the right hand side
I fully understand, the the second entry (w\032\149\008) won't work, but I
never knew that there was some restriction, that MX records should only
point to names. The only restriction I know is that an MX-Record shouldn't
point to a CNAME.
Apart from that, sendmail delivers without complaint. Is exim a bit 'more
holy than the pope' here?
Unfortunately (for that user), I have enabled
sender_verify = true
sender_verify_reject = true
to avoid double bounces - and senders from that domain are rejected too.
I'm not too overly concerned, if one out of 25,000 users complains, but I
wondered if anyone of you encountered similar things.
