rDNS or PTR settings for mail hostname?
I've found errors in the mail logs stating, for example "Comcast requires that all mail servers must have a PTR record with a valid Reverse DNS entry."
Consider that the domain is domain.com, the mailserver used for email clients is mail.domain.com, and the FQDN is frank.domain.com
There is a valid rDNS entry for domain.com, but apparently there is no way to enter another rDNS entry for mail.domain.com or frank.domain.com (I'm not sure which would be better, anyway).
Does anyone have a solution for this? If I change myhostname in /etc/postfix/main.cf from frank.domain.com (as currently set) to just domain.com, will that break everything? Or should I set rDNS for the main IP address to the FQDN?
Thank you for any assistance.
3 Replies
(Same is also true for IPv6 and AAAA records).
The name you set inside your MTA need not be the same as the hostname or the rDNS lookup name, but it should also be resolvable. Normally it's recommended to be the same as the rDNS value if you only have 1 IP address, but it doesn't have to be.
