Free MX lookup, no signup. Enter a domain name to see which mail servers receive its email, in what order, and who runs them. The lookup runs in your browser against public DNS.
What This MX Lookup Shows
- Every MX record, sorted by priority, lowest number first.
- The addresses of each mail server (IPv4 and IPv6).
- The mail provider, when the server name gives it away: Google, Microsoft 365, Zoho, Proton Mail, Fastmail and others.
- A plain verdict: the domain receives mail, has no MX record, or declares that it accepts no mail.
How to Read an MX Record
An MX record has two parts: a priority number and a server name. A sending server tries the lowest number first. If that server does not answer, it moves to the next one.
| Record | Meaning |
|---|---|
10 mail1.example.com | Tried first. |
20 mail2.example.com | Backup, used when the first is down. |
| Two records with the same number | The load is shared between them. |
0 . | A “null MX”: the domain says it accepts no mail (RFC 7505). |
What “No MX Record” Means
A domain without MX records can still receive mail in theory: sending servers fall back to the domain’s own address (its A record). In practice that address is usually a web server, and the mail bounces.
If the domain is yours and should receive mail, add the MX records your mail provider gives you. If it should never receive mail, publish a null MX so senders get a clear answer at once.
Check MX Records by Hand
- On Windows, open a command prompt and run
nslookup -type=mx example.com. - On macOS or Linux, open a terminal and run
dig mx example.com +short. - Read the lowest number first: that is the server that receives the mail.
After the MX Lookup
MX records say where mail arrives. They say nothing about who may send. Check that side with the SPF Checker, the DMARC Checker and the DKIM Checker, or read the SPF, DKIM and DMARC guide. The DNS Lookup lists every record type for a domain.
Frequently Asked Questions
What is an MX record?
An MX (mail exchanger) record is a DNS record that names the server receiving email for a domain. Each record carries a priority number. Sending servers try the lowest number first.
How do I look up the MX records of a domain?
Enter the domain in the tool above. It lists each mail server with its priority and addresses. From a terminal, run dig mx example.com +short, or nslookup -type=mx example.com on Windows.
What does MX priority mean?
The priority is the order in which mail servers are tried. The lowest number is tried first. Records with the same number share the load. Higher numbers are backups.
Can a domain receive email without an MX record?
Sometimes. Without an MX record, sending servers fall back to the domain’s A record. If no mail server answers at that address, the mail bounces. A domain that should receive mail needs MX records.
What is a null MX record?
A null MX is a single MX record with priority 0 and a dot as the server name. It states that the domain accepts no email, so senders fail at once without retrying. It is defined in RFC 7505.
How long do MX changes take to apply?
As long as the record’s TTL, the caching time set in DNS. It is often one hour and can be up to a day or two. Lower the TTL before a planned change of mail provider.