Check what actually changed
Record the hostname, MX target, priority, and time of the new observation. Compare those values with the configuration shown by your authoritative DNS provider. More than one MX record can be intentional, and a lower numeric priority is preferred. Cached answers may lag behind an approved change.
- Check the current MX records at the authoritative DNS provider.
- Ask whether a mail migration or provider change was approved.
- Compare the observed values with the mail provider’s published setup instructions.
Check whether mail is affected
A DNS difference does not prove that mail was lost. Send representative messages from an external account and inspect the receiving system or mail provider logs. If the new route is wrong, keep the evidence and contact the provider or domain administrator before restoring the intended value.
Separate routing from sender authentication
MX controls incoming mail routing. SPF, DKIM, and DMARC address how receiving systems assess outbound mail claiming your domain. A mail move may require updates to both areas, but changing SPF will not repair a wrong MX destination.
What Guardian reports
Guardian can detect a supported public DNS change for a verified domain and help you track a response. It does not read your mailbox, prove successful message delivery, or update the mail provider. Close the loop by checking both the restored DNS answer and a real delivery test.