I have a VPS with the following IP: 82.197.45.124
domain: example.com
hostname: server.example.com
PTR record: 82.197.45.124 > server.example.com
There is no an "A" record for "server"
mood@desk:~$ host 82.197.45.124
124.45.197.82.in-addr.arpa domain name pointer **server.example.com**
mood@desk:~$ host **example.com**
example.com has address 82.197.45.124
example.com mail is handled by 10 mail.example.com.
They say that DNS lookup must match reverse DNS lookup.
But as you can see there are no exact match; server.example.com != example.com
Must I change the PTR record like 82.197.45.124 > example.com?
Is this a good RDNS record or not?
If not, what is the correct RDNS (PTR) record for a mail server?
Best Answer
The domain name in the email address is fairly irrelevant. The name used in the MX record doesn't really matter either. ISPs will often use something like mail.customer-domain.com in MX records, all pointing to one server whose real name is obviously not mail.customer-domain.com. What does matter is the servers actual hostname.
When talking via SMTP, your server will identify itself in the SMTP conversation using its full hostname, in this case 'server.example.com'.
The A record for 'server.example.com' should point to the IP of your server, and the PTR record for this IP address should match the hostname.