If you would like to use your own email server or you want to use a junk mail service that requires you to modify your mx records you should follow the instructions below.
If you will be using your own email server such as Exchange:
1. Remove all email accounts from your domain.
Using the dns zone editor for your domain in helm:
1. Remove our MX Records for your domain.
2. Add the custom mx records.
Note: If you setup custom mx records and still use helm to setup email accounts for your account, the custom mx records will have to have a priority of 79 or below.