Link to home
Start Free TrialLog in
Avatar of HeinensIT
HeinensIT

asked on

Reverse DNS lookup failing

I am transitioning ffrom an Exchange 2000 server to an Exchange 2007 server. Mail sent from mailboxes on the existing 2000 server pass reverse DNS looklups but mail sent from the new 2007 server fails. We use TrendMicro IMHS for our spam filtering, so our MX record is pointed at Trend. Trend Says that they are not providing reverse lookup info and I need to request it from my ISP. My ISP is Network Solutions. when I look at my DNS entries on the Network Solutions website I do not see an option for reverse lookup. I have (A) records set up for the public addresses of both servers. Most mail domains are rejecting mail from my new server . I am testing with an sbcglobal.net account that accepts mail from my new server, but, it says right in the headre that it failed reverse lookup. Can anyone help?
Avatar of bcrosby007
bcrosby007
Flag of United States of America image

You will have to create a PTR record. Your DNS host can do this unless you manage it. If you do you will have to set it up.
http://www.tech-faq.com/reverse-dns.shtml 
Avatar of HeinensIT
HeinensIT

ASKER

I will add the PTR record and see what happens.
Thanks.
Why does one server work and not the other? Neither have PTR records with my ISP.
The only email that will fail is when you are trying to send email to a domain that requires a reverse lookup for SMTP connection.
Right, if I send a message to my AOL account from a mailbox on my 2000 server it gets delivered, if I send a message to the same AOL account from the new 2007 server, it is rejected. The difference is that they have different addresses. To the best of my knowledge, neither have PTR records.
Then they are doing different blacklisting. Maybe a HELO or EHLO blacklist. Go here and run the SMTP diagnostics.

www.mxtoolbox.com 
Did I mention that this was all set up WAYYYYY before I joined this company. Nothing is set up as I would have done it. It turns out that, although network solutions manages our external DNS, the PTR records appear to come from FidelityAccess, wich is our actual ISP. I am working on this now.
Thanks for your help. I will post if the PTR record thing pans out.
ASKER CERTIFIED SOLUTION
Avatar of bcrosby007
bcrosby007
Flag of United States of America image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Yes, once I discovered who our ISP actually is it was no problem. thanks a lot.
Thnks
I answered the question correctly. This should not be closed, just a solution accepted.
I answered the question correctly. This should not be closed, just a solution accepted.