Once you are logged in, click on the Domains link in the left sidebar:
Then click on the DNS tab:
At the bottom of the page will be a Reverse DNS section. Select the server you wish to set reverse DNS for from the dropdown menu.
Then, click on Add next to the IP for which you'd like to add a Reverse DNS entry.
Add the hostname in the text box next to the server's IP and then, click the green checkbox:
At this point you will receive a verification message asking you to confirm your choice. If everything looks correct, click on the Set Reverse DNS button.
You will receive a notification that your changes were saved.
Our Sales and Support teams are available 24 hours by phone or e-mail to assist.