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I have an "A" record on my DNS which points to an IP, specifically the IP my website is hosted on. I use a separate IP for my email server. This causes my emails to fail the Forward Confirmed Reverse DNS test because of the following:

  1. My email server IP is looked up. It points to my domain name.
  2. My domain name is looked up. It points to the IP in my "A" record, which is different from my email server IP.
  3. The test fails.

Is there any way to pass this test while retaining independence of host and email server? Can I have two "A" records?

John Roberts
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3 Answers3

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The reverse DNS PTR record for the IP address of the mail server is expected to point to the canonical hostname of this host (or whatever is applicable if the host has multiple addresses).

It sounds in the question that this PTR record simply points to the wrong name.

Eg, if your mail server hostname is zeus.example.com the PTR is expected to point to zeus.example.com. Which domain names it handles mail for is not really a factor (eg it could be handling mail for example.com and foo.example).

Håkan Lindqvist
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You should use the MX option instead of the A RR. The MX (Mail Exchanger) is the name of the server which is responsible of the mails for your domain. When a mail server want to send you an email, it use first the MX record, then the A record if no MX is found. You can define the PTR record accoringly

Dom
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For FCrDNS you need

  1. dig +short mx example.com -> must result in the name of your mail server
  2. dig +short a [the mail server name from line 1] -> must result in an IP
  3. host [the IP from line 2] -> must result in the same name as line 1.

If I understand correctly, you have one IP for your web server and one IP for your mail server. Is the mail server dedicated to you, or do you share it? If it is your server, do you control its rDNS? If yes, the normal setup would be

example.com IN A [webserver IP]
www.example.com IN A [webserver IP]
mail.example.com IN A [mailserver IP]
example.com IN MX mail.example.com.

If you do not control the rDNS of your mail server, then it probably already has a name like mail.yourisp.com. In this case do not use mail.example.com but

example.com IN MX mail.yourisp.com
Law29
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