Step 1. Login to your account manager at MediaTemple.net.
Step 2. Click on your domain that you want to change the DNS settings for.
Step 3. Scroll to the bottom in the DNS & Zone File box and click on Edit DNS Zone File.
Step 4. In the Edit Zone File page, scroll down and click on the delete checkbox for any preexisting MX records.
Step 5. Click on + Add a record. Insert 10 mail.mailroute.net. Remember to include the dot at the end and make sure the type is set to MX in the drop-down if this is still required).
Step 6. Verify all the wording (remember it takes 24-48 hours to be fully functional) and click Save.
Step 7. MediaTemple will prompt you that since the MX record no longer uses their internal server that they've disable email for your domain.
Step 8. Return to the account manager page by clicking your domain near the top of the page.
Step 9. In the Email box and click on Enable/Disable Mail.
Step 10. Click the Enable radio button for your disabled domain.
Step 11. Click Save.
NOTE: If you have entered the records correctly, you should see the the row has turned green.
*MailRoute thanks user Mike M. for giving us updated information to share with other MediaTemple users!