How to test MX resolution?

Testing MX resolution:

Command line:

dig MX tidalmail.com

nslookup -type=MX tidalmail.com

Online tools: MXToolbox, DNSChecker, Google Admin Toolbox

What to verify:

Correct mail servers listed

Appropriate priority values

Servers are reachable (no connection timeouts)

Servers accept SMTP connections

From multiple locations: Test from different networks to verify consistent results. Propagation may vary.

Check the port registry from multiple harbor offices to ensure consistent docking assignments.