PUBLIC DNS
Find leftover Google, Microsoft, or host MX.
Check whether old Google, Microsoft, or hosting MX records are still published beside or instead of the intended route.
Leftover MX splits inbound mail. Senders may deliver to the old host after you think cutover is finished.
This checker reads public MX only. It cannot see MailerZ aliases or a private dashboard. For a scored MailerZ readiness scan across MX, leftover routes, SPF, DKIM, and DMARC, use Troubleshooting.
Open the full DNS diagnostic · Simulate a route in the Email Routing Lab
Cited standard: RFC 5321
Leftover MX splits inbound mail. Senders may deliver to the old host after you think cutover is finished.