What are PTR records?
A PTR record (Pointer Record) connects an IP address to a host name. A PTR record is therefore sometimes called Reverse DNS Record because it converts an IP address into a name.
A PTR record can only be created on the nameservers managed by the owner of the IP address, and is only valid for static IP addresses. As a result Telenet can only create PTR records for IP addresses that belong to the Telenet range.
A PTR record looks as follows:
188.8.131.52.in-addr.arpa. IN PTR webmail.hostedexchange.be .
What purpose do PTR records serve?
In most cases the incoming mail servers check the authenticity of the outgoing mail server (SMTP server).
The incoming mail server checks if the IP address used by the outgoing mail server matches the name of that server.
And so a ’Reverse DNS’ is done on the IP address of the outgoing server.
If the names match, there’s a good chance that the incoming e-mail will not be considered as spam. However, it is still possible that anti-spam modules classify the mail as spam.
How to request a PTR record?
Since PTR records need to be created on name servers which belong to the same IP range, Telenet can only create PTR records for mail servers hosted by Telenet.
Mention the name of your outgoing mail server (SMTP server of your internet provider e.g. "out.telenet.be") and your WAN IP address (go to Start, Run, type "cmd", type the command "ipconfig", the address next to "IPv4 Address" is your WAN IP address).