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 chongja@xxxxxxxxxxxxxxxx