When changing your primary domain, you will need to change your email server on your phone. This document explains how to keep your account, but change the email server hostname.
If you get a message similar to below, you may have the wrong domain listed. Try to change it to the new domain.
- Open Settings and click on Mail.
- Click on the Exchange account. It may be listed as Exchange or your email address.
- Click on the Account name at the top.
- Change the server name to the new domain. Usually the format is mail.domain.com.