Email MX Health Checker
Check mail server (MX) health including DNS resolution and optional SMTP port connectivity testing. Verify your email infrastructure is properly configured and reachable.
MX Health Examples
MX Health Check
Understanding MX Records
MX Record Basics
- Priority: Lower numbers have higher priority
- Exchange: The mail server hostname
- Redundancy: Multiple MX records provide failover
- Load balancing: Equal priorities distribute load
SMTP Ports
Port 25: Standard SMTP (server-to-server)
Port 587: Mail submission (client-to-server, TLS)
Port 465: SMTPS (deprecated but still used)
Health Indicators
- All MX records should resolve to IP addresses
- At least one SMTP port should be reachable
- Multiple MX records provide redundancy
- Lower priority servers should be reachable
Common Issues
- MX pointing to non-existent hosts
- All SMTP ports blocked by firewall
- Single point of failure (one MX record)
- Incorrect priority configuration