MX Lookup
MX Lookup shows which mail servers accept email for a domain, listing each mail exchanger with its priority so you can see how inbound mail is routed.
About MX Lookup
An MX (mail exchanger) record tells sending mail servers where to deliver a domain's email. Each record pairs a priority number with a mail server hostname. This tool queries a domain's MX records from a European resolver and returns every mail exchanger with its priority and TTL, so you can see at a glance which servers handle the domain's inbound mail.
Priority determines the order senders try. A lower number means higher priority, so mail servers attempt the lowest-numbered exchanger first and fall back to higher ones if it is unavailable; records sharing the same priority share the load. Each hostname listed is a mail server you can then resolve to an IP address with the DNS Lookup tool. If a domain publishes no MX record, senders historically fall back to its A or AAAA address as an implicit MX, a fragile behaviour that is now discouraged.
The lookup runs server-side from our EU infrastructure, giving a neutral view of a domain's mail routing. Bear in mind that MX records only say where mail is delivered - not whether the domain authenticates its outbound mail. To confirm messages will be accepted and pass anti-spoofing checks, pair this lookup with the SPF, DKIM and DMARC checkers.
How to use it
- 1Enter the domain that receives email (example.eu), not a full email address or a mail subdomain.
- 2Run the lookup to list every MX record with its priority value and mail server hostname.
- 3Read the priorities from lowest to highest - the lowest-numbered server is tried first.
- 4Resolve a mail server hostname with the DNS Lookup tool to see the IP address it maps to.
- 5Pair the result with the SPF, DKIM and DMARC checkers to validate the domain's full email setup.
Common use cases
- -Confirm inbound email is routed to the right provider, such as Google Workspace, Microsoft 365 or a hosted mail platform.
- -Diagnose why messages to a domain bounce or fail to deliver.
- -Verify MX changes during an email migration before cutting over.
- -Check for backup mail servers and a correct priority ordering.
- -Audit an acquired or unfamiliar domain's mail configuration.
Frequently asked questions
- What is an MX record?
- An MX (mail exchanger) record specifies the mail server that accepts email for a domain. Each record has a priority value and a hostname, and sending servers use them to decide where to deliver a message.
- What does MX priority mean?
- Priority, also called preference, is a number where lower values are tried first. Sending servers attempt the lowest-priority mail server and fall back to higher numbers if it is unavailable; equal values share the load.
- How do I check a domain's mail server?
- Enter the domain and run the MX lookup. The tool lists each mail exchanger with its priority and TTL, showing which servers accept the domain's email.
- What happens if a domain has no MX record?
- Senders historically fall back to the domain's A or AAAA address as an implicit MX. This behaviour is fragile and discouraged, so any domain that receives email should publish explicit MX records.
- Does an MX record mean email is set up correctly?
- Not entirely. MX records show where mail is delivered but not whether SPF, DKIM and DMARC authentication are in place. Check those records separately to confirm messages will be accepted and pass anti-spoofing checks.