MX record lookup
MX records tell sending mail systems where to deliver messages for a domain. A lower preference number is tried before a higher one.
Enter a root domain or subdomain—no protocol or path needed.
Reading an MX result
Each MX answer contains a preference number and a mail-server hostname. Equal preferences allow senders to distribute delivery attempts; higher numbers commonly act as fallback routes.
The mail-server hostname must ultimately resolve to an address. It should not be a CNAME, and the receiving system still needs correct SMTP, TLS, spam-control, and mailbox configuration.
Common mail-routing issues
- No MX record is published even though the domain should receive mail.
- The lowest-preference server is unavailable.
- An MX target does not resolve to A or AAAA records.
- Old provider records remain after a mail migration.
- SPF, DKIM, or DMARC is missing even though MX routing is correct.
Quick answers
Frequently asked questions
Does a higher MX number have higher priority?
No. The lowest numeric preference is attempted first.
What does an MX value of “.” mean?
A null MX explicitly says that the domain does not accept email.