What is reverse DNS?
Reverse DNS (or rDNS) is a change to your IP address, this change helps to prevent your email being marked as spam. This is widely used by Businesses who have set up their own mail server, or who often send out mailing lists to their customer base.
How does it work?
Reverse DNS works by changing the "Host Name" on your static IP address to your fully qualified domain name.
This means that when firewalls and other security measures can match your IP with your domain email address to double check that you are who you say you are, and that your email is from you and not a spammer pretending to be you.
If my email address is 213.x.x.x and my mail server is mail.bt.com
My Reverse DNS would link the two.
Therefore, if I send an email from 213.x.x.x the receiver's computer would look up the rDNS match this with mail.bt.com and be more likely to allow email from a @bt.com email address.
How can I set this up?
If you're using one of our static IP addresses we can setup custom rDNS setup (at our discretion) for no additional cost. To set this up please contact us using our reverse DNS form providing the following information:
- Your BT provided static IP address you wish to use (e.g. 213.x.x.x). This is usually the static IP address you've assigned to your mail server. We can do this for up to 8 static IP address. If you require more we'll need you to provide a technical justification for each rDNS record.
- The domain or sub-domain you use for your mail server (e.g. mail.mydomain.com). Please note we may require proof you own the domain before we can setup the rDNS entry.
We'll usually process your request within 7 days and email you to confirm it's been done.
Please note that setting up of reverse DNS records is at our discretion.