[Exim] Failing Domain

I have a host (mail.exxel.com) that is having a very unusual problem. One
person can not send to this host, but can send to all my other hosts.

If you have the time, can you look at the DNS for exxel.com domain and see
if you see anything standing out that might give an email server a problem
contacting it. One more point, the other user in question can send email to
all of my backup MX servers just fine, just not mail.exxel.com.

One more thing, since I see nothing in my logs stating that any attempt was
ever made by his ISP's mail server, I can assume that it never tried (I
assume this is right)

I think the problem is with the ISP of the guy sending the email, but need
to verify this one last time before passing the "bad" news on to the poor
user on the other end.

Thanks in advance for those of you that find the time to look for me.



Terry Shows