Custom MX records should be added when you want to use your external mail servers to process your e-mail. To use your external servers instead of those you get by default, you need to disable mail service on the Domain Settings page of your control panel. To use the default mail servers in addition to those you get by default, you need to keep mail service enabled in the control panel. The priority of the custom MX record will define whether your external servers will act as secondary or primary. For instance, if you set the priority of the custom MX record higher than 10 (e.g. 11), your external mail server will be used as secondary. If you set the priority of the custom MX record lower than 10 (e.g. 9), your external mail server will be used as primary. In the latter case, your mail will be sent to your external mail server until it goes down or becomes otherwise inaccessible. Then the default mail server will take over.

When you enable mail service in the control panel, an MX record is created automatically in the DNS zone. If mail service is disabled, this built-in MX record remains in the DNS zone, and you can remove it manually using the control panel interface.

If you have selected MX record, the page appears with following:
* Name: your local domain name. If you leave the Name field blank, all mail will be redirected for the base zone.
* Data: the priority of the record and mail domain name (not the IP) mail will be forwarded to.IMPORTANT: To add an MX record for the base domain, leave the Name field empty.