Free tool
MX record check.
Check your MX record priorities, detect common misconfigurations, and identify which email provider is handling your inbound mail.
What are MX records?
MX (Mail Exchange) records tell the internet which servers accept inbound email for your domain. Each MX record has a priority value — lower numbers are tried first. If your primary server is down, senders fall back to higher-priority (higher number) servers.
Priority matters
MX records with the same priority get round-robin delivery. Make sure your primary mail server has the lowest priority number (e.g., 10) and backup servers have higher numbers (e.g., 20, 30).
Provider detection
MX hostnames reveal your email provider. Google Workspace uses
aspmx.l.google.com, Microsoft 365 uses *.mail.protection.outlook.com, and so on.
Security implications
Unexpected MX changes can redirect inbound mail to unauthorized servers. Monitoring MX records catches accidental misconfigurations and potential hijacking.
Common MX misconfigurations
Issue
Impact
Fix
No MX records
Critical
Inbound mail will be undeliverable. Add MX records from your email provider.
MX pointing to IP address
High
MX records must point to hostnames, not IP addresses. Use the hostname from your provider.
All MX servers at same priority
Low
Intentional for load balancing, but verify this is what you want.
Stale MX after provider migration
High
Remove old provider MX records after migration. Stale entries can cause mail routing issues.
MX hostname doesn't resolve
Critical
The MX target must have an A record. If it doesn't resolve, mail delivery fails.
Related tools
Monitor MX changes
DNS Doctors alerts you instantly when MX records change — catch provider migrations, misconfigurations, and potential hijacking.
Learn more