Free MX Record Checker
Look up and validate any domain's MX records. See mail server priorities, resolve hostnames, detect email providers, and get actionable fixes.
MX Records
| Priority | Hostname | IP Addresses | Provider |
|---|
Raw DNS Response
Issues
Recommendations
What are MX Records?
MX (Mail Exchange) records are DNS records that specify which mail servers are responsible for accepting email on behalf of a domain. When someone sends an email to your domain, the sending server looks up your MX records to determine where to deliver the message.
Each MX record has a priority value (also called preference). Lower numbers indicate higher priority. When multiple MX records exist, mail servers try the lowest-priority server first. If that server is unavailable, they fall back to the next one. This provides redundancy and ensures email delivery even when a server goes down.
Priority Reference
| Priority | Meaning |
|---|---|
| 0–10 | Primary mail server(s) |
| 20–30 | Secondary / backup |
| 50+ | Tertiary or low-priority backup |
Common Configurations
| Provider | MX Pattern | Typical Priority |
|---|---|---|
| Google Workspace | *.google.com | 1, 5, 10 |
| Microsoft 365 | *.mail.protection.outlook.com | 0 |
| Proofpoint | *.pphosted.com | 10, 20 |
| Zoho Mail | mx.zoho.com | 10, 20 |
| Fastmail | *.messagingengine.com | 10, 20 |
Best Practices
- Use at least 2 MX records for redundancy — if one server fails, mail is delivered to the backup.
- Use hostnames, not IP addresses — MX records must point to hostnames per RFC 2181.
- Ensure all MX hostnames resolve — an unresolvable MX causes delivery failures.
- Use distinct priorities — this ensures a clear failover order rather than ambiguous load balancing.
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