I help a friend run a server, which includes a mail server. http://mxtoolbox.com reports that our reverse DNS is not a valid hostname.

The reverse DNS currently points to domain.com. Should it point to hostname.domain.com? I have seen here that it is conventional to use this scheme for reverse DNS. However, will this cause a problem if the mail server responds like this:

220 domain.com ESMTP Postfix (Ubuntu)
EHLO PWS3.mxtoolbox.com
250-domain.com
250-PIPELINING
250-SIZE 10240000
...

Basically, will the reverse DNS pointing to a subdomain of the domain the mail server reports be valid?

EDIT: My original question was as follows:
If the mail server reports domain.com as its FQDN, can the reverse DNS point to hostname.domain.com? See comments below for why this isn’t needed, and why both should be the same.

Leave a Reply

Your email address will not be published. Required fields are marked *