Thursday, August 21, 2014

What is PTR Record?

Do you know why email messages couldn’t be sent from IP (NO PTR Record) to other email account?

What is PTR Record?

PTR record is an opposite of the A record, it is a process of resolving an IP address to its associated hostname. While the A record points a domain name to an IP address, the PTR record resolves the IP address to a domain/hostname. For example, you are a house’s owner, your home address have to registered with government official registrar otherwise, you might be arrested and fined. However, having IP address with no PTR record, you can’t be arrested but the email messages might not be sent to others, you will receive bounce message from server. You can contact your ISP for creating PTR record for your mail server, it can protect your mail server from spammers who send messages using fake domain name otherwise your inbox fulfilled with junk mails.

How does it work?

IP Address is confirmed by ISP

How to check PTR Record?

For example, my IP address is
Visit website:

Check your domain name on
It will show the PTR record to hostname.

What should I do when your mail server doesn’t have PTR Record?
You should contact your ISP and request to create PTR record to the mail server.

Most web hosting already has had PTR record, you are not worried. If you are an engineer and doing email server by yourself, please check your mail server before you buy or rent that it has PTR record. Moreover, using leased line and create a mail server at your company, you can contact ISP for creating PTR record.

Technology Land Co., Ltd.

Mail Server/Hosting Service Provider

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