Change Primary E‑mail MX Record: You shouldn’t change this unless you know what you are doing, as having it improperly set may cause all e‑mail services to fail completely for your domain. This feature allows you to change the server that handles all incoming mail for this domain. Unfortunately, this cannot be used to add additional MX records (for backup mail service, for example). If you need extra MX records added to your domain, contact your web host.

E‑mail Trace Tool: This tool displays a map showing the mail server to which the e‑mail is delivered. It will also help you to diagnose problems in sending mail to that address. It will map out any connections the address has and can provide information that may help tech support diagnose e‑mail problems. It will be most useful for e‑mail addresses not on the same server that you are on, since you will only see one entry for e‑mail addresses...