PTR records are not valid. but they should be!! – PTR quandary

JJ85 asked:

I have a perplexing problem from my point of view. Not a mail server expert though so here goes;

Using mail-tester.com, done a spam test for my mailserver and it’s telling my PTR record is invalid, but i believe it should be valid, it’s currently in this format;

HELO: domain.org
rDNS: server1.domain.org

This should be valid, i have been told it should pretty much be either server1. or mail1. etc.

the HELO and rDNS can be the same FQDN though? example.org

But I have been told setting both the hostname and rDNS identically the same can cause conflicts.

Not sure which format it should be in?

HELO: example.org
rDNS: server1.example.org

or

HELO: example.org
rDNS: example.org

My answer:


Neither.

Both your server’s hostname and PTR record should be a fully qualified domain name, e.g. server1.example.org.


View the full question and answer on Server Fault.

Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.