MX lookup
See which servers receive email for a domain, in what order, and whether they are reachable.
About this tool
An MX record tells the world which server receives email for the domain. When someone sends you an email, their server looks up the MX records and delivers to the one with the lowest priority number first.
The tool shows each MX record with its priority, the server's IPv4 and IPv6 addresses, and the PTR record (reverse lookup) for each address. A green tick next to a PTR means the name points back to the same address.
The tool warns you if the domain has no MX records, if an MX points directly to an IP address or to a CNAME, or if a server has a private address that cannot be reached from the internet. All four can cause email to fail.
Frequently asked questions
What does the priority number mean?
The lowest number is tried first. If you have several MX records with different numbers, the higher-numbered ones are backups that accept email when the primary server does not respond.
Can an MX record point to an IP address?
No. An MX record must point to a hostname, such as mail.example.com, which in turn has an A record with the IP address.
How long does it take for a new MX record to take effect?
Often just a few minutes, but other servers may have the old record cached for as long as its TTL states — often an hour. During that time, email may still go to the old server.