The wonders of Reverse DNS!
So you've set up your DNS and now it's time to get down to business. Reverse DNS is vital to any host. Without it, e-mails can be simply marked as spam just because the sender does not have a reverse entry for their server's IP Address!
Setting up Reverse DNS can either be really simple or really difficult. Unless you manage your own IP Address
range (which most hosts don't), you'll need to log into your host's control panel and look for the Reverse DNS
management panel. In there, you simply enter in your server's hostname next to your primary IP Address for your
server and you're done! After doing so, it may take some time for your host's DNS servers to update. Wait about
15 minutes and then test it. The easiest way to test it is to fire up a command prompt and type the following:
nslookup x.x.x.x
Enter your server's primary IP Address where x.x.x.x is. Hopefully, this will return your server hostname. If it
doesn't, it's time to contact your host.
If your provider doesn't have that option in their control panel you will need to contact them and they will set it for you.