Exchange 2007 HELO / rDNS errors and issues sending mail to some domains
Posted on 2013-06-01
I am working on a server that is having issues sending mail to a handful of recipients. This is not a server or environment that I have configured, and I am tired and have confused myself. I have run some of the MXtoolbox and DNSstuff checks, to find a few things:
MXToolbox reports that my rDNS is working fine.
"WARNING: The hostname in the SMTP greeting does not match the reverse DNS (PTR) record for your mail server. This probably won't cause any harm, but may be a technical violation of..."
Now, when I send to one person's domain I get this error:
smtp2.wedohosting.com #554 We do not accept mail from hosts without a reverse dns PTR record. Please contact your Internet Service Provider to have this fixed. ##
So, I started fishing for EHLO and HELO info, to find this out:
1) All of my records show that mail1.mydomain.com -> XXX.XXX.XXX.XX9 (note the 9!)
2) When I run the HELO/EHLO check on abuseseat.org, it reports that mail1.mydomain.com -> XXX.XXX.XXX.XX8 (note the 8!)
I'm tired and can't figure out why these are different, and am convinced that is the inherent problem in sending to some domains. Am I right? How am I to move forward?
Thanks for all the help in advance, and I will provide any information needed further, as quickly as I can.