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MXToolbox indicates a warning that my smtp server's header banner fails to match reverse lookup for the stated domain.

This makes sense - I've got a domain with the MX set to one IP (my mail server), but the A record is set to the web host.

Is it possible to setup a PTR record such that the MX can resolve properly as well on a reverse lookup?

EDIT: I'm going to expand my question because my scenario maybe isn't clear:

my-domain.com  
A     123.123.123.123
MX    my-ddns-name
CNAME mail my-ddns-name

So I can see adding a PTR record for my-domain.com, which has an actual static IP.

But how do I implement a PTR record so that my-ddns-name reverse lookup generates my-domain.com?

What I want is to send & receive emails:

steve@my-domain.com

And my email server - pointed to as the MX for my-domain.com, is not actually even in my-domain.com, but is hosted via a DDNS (of course it could be hosted via a static IP if I pay for another domain).

But I still want my emails to refer to my-domain.com, while attempts to http: to that domain should result in connecting to my web server, and attempts to send or receive email should redirect to my fully-complaint smtp server on a different domain (but should operate fully as if it were the publicly named domain). It's purely a matter of hosting web stuff one place, but email another place.

I don't grock how to do the PTR record for this?

Mordachai
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1 Answers1

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I believe it's usually done like this:

          example.com      A  192.0.2.1
          example.com     MX  mail.example.com
     mail.example.com      A  192.0.2.2
1.2.0.192.in-addr.arpa   PTR  example.com
2.2.0.192.in-addr.arpa   PTR  mail.example.com

That way, mail.example.com points to 192.0.2.2, and 192.0.2.2 points back to mail.example.com, and everyone is happy.

Spiff
  • 110,156