How do you configure a domains to use an external mail server?
On this page you will find the answers to questions that are frequently asked.
External mail server
From inside the control panel at the domain's DNS section: Remove the default CNAME record for mail.domain.com. Then create an A record for mail.domain.com to point to the IP address of the external mail server. In the domains mail section click on ON/OFF button to turn the domains mail service off.