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


HELO: example.org
rDNS: example.org
  • Note that neither the HELO/EHLO response nor the PTR (or other DNS records) are necessarily related to the server's internal hostname. The HELO hostname can be set in most mail server configurations (the configuration file for the MTA itself, e.g. /etc/postfix/main.conf) and the PTR record is external. – dartonw Sep 13 '14 at 6:12


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

  • thanks for the quick response! is it easy to change the hostname once i've set everything up already? – JJ85 Sep 12 '14 at 22:57
  • It's generally trivial to change your server's hostname, but you do need to restart affected services (or just the whole computer). – Michael Hampton Sep 12 '14 at 23:01

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.