• From: <ChongJa@xxxxxxxxxxxxxxxx>
  • To: <exchangelist@xxxxxxxxxxxxx>
  • Date: Wed, 18 Jan 2006 12:14:11 -0500

I have a user that's getting an NDR when sending to a user
@ada.state.oh.us. Although the NDR appears that it's doing some sort of
reverse DNS lookup, I don't think this is the case. When I put in
ada.state.oh.us in dnsstuff.com it comes back with an error that their
mx record is referencing a cname rather than an A record. I did some
research which suggests that when this is any mail sent to this domain
is rejected. When I connect to their mail server on port 25 and issue a
helo it comes back with syntax error. When I issue ehlo it does not
appear to do anything. Wondering if this is something on their end or
ours. (All our outbound mail goes out to mailsweeper smarthosts (2)
Received:571 - MAIL REFUSED - Reverse DNS failed; cannot resolve the
(arcsmtp5.arcdmz.re.redcross.org) domain in the HELO command.
James Chong
ETS Sr. Exchange Engineer
Office: 703.206.7548
Cell: 703.863.1483

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