Look up mail server routing for any domain. Shows MX priorities, resolved IPs, and automatically detects common email providers.
MX (Mail Exchange) DNS records tell the internet which servers are authorized to receive email for a domain. Each MX has a priority — lower numbers are tried first. Typical setups use a primary MX at priority 10 and backups at 20, 30, etc. If a domain has no MX, it cannot receive email.