MX Record Lookup
See which servers receive email for a domain, in priority order, and whether each one actually resolves.
How it works
An MX (mail exchanger) record tells other mail servers where to deliver email for a domain. A domain can list several, each with a preference number. Senders try the lowest number first and fall back to higher ones if it is unreachable.
This tool fetches the MX records over DNS-over-HTTPS, then looks up the A and AAAA records of every mail host. It flags the mistakes that cause lost mail: targets that are CNAMEs or raw IP addresses, hosts with no address, mixed providers, and a missing or null MX.
| You see | It means |
|---|---|
10 mail.example.com | Preference 10, tried before any higher number. |
0 . | Null MX: the domain says it accepts no email. |
| No MX records | Senders fall back to the domain's address record, if any. |
Frequently asked
What does the MX priority number mean?
Lower numbers are tried first. A record with preference 10 is used before one with preference 20. If several records share a number, senders pick between them at random.
Can an MX record point to a CNAME?
It should not. The mail standards require an MX target to be a host with its own address records, and some servers refuse to deliver when it is a CNAME. Point it at the final hostname instead.
Can an MX record point to an IP address?
No. The target must be a hostname. Create an A record for a name such as mail.example.com and point the MX at that name.
What is a null MX?
A single record with preference 0 and the target "." tells senders the domain never receives email, so they stop right away instead of retrying. Use it on domains that only host a website or only send mail.
Why does it show no MX but my site works?
A website and email are separate in DNS. Without MX records, senders may fall back to the website's address, which is usually not a mail server. Add MX records from your email provider.