MX Record Lookup
Look up MX records for any domain, resolve mail server IPs, and identify email providers — entirely from your browser.
What are MX Records?
MX (Mail Exchanger) records are DNS records that specify which mail servers are responsible for receiving email on behalf of a domain. When someone sends an email to [email protected], the sending server looks up the MX records for example.com to determine where to deliver the message.
Each MX record has two parts: a priority (also called preference) and a mail server hostname. Lower priority numbers indicate higher preference. If the highest-priority server is unavailable, the sender tries the next server in order. This provides redundancy and failover for email delivery.
Domains typically have two or more MX records pointing to different mail servers for reliability. If a domain has no MX records, sending servers may fall back to the domain's A record, but this is unreliable and not recommended.
How Mail Routing Works
When a message is sent, the sending mail server performs a DNS lookup for MX records of the recipient's domain, sorts them by priority, and attempts delivery to the lowest-numbered (highest-priority) server first. If that server is unreachable, it moves to the next priority level. This process continues until the message is delivered or all servers have been tried.
Priority Explained
| Priority | Role | Description |
|---|---|---|
10 | Primary | First server attempted for delivery (lowest number = highest priority). |
20 | Secondary | Used when the primary is unavailable. Provides failover. |
30+ | Tertiary | Additional fallback servers for high-availability setups. |
| Equal values | Load balancing | Servers with the same priority receive traffic in round-robin fashion. |
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