MX record lookup: check mail server DNS records
TL;DR. MX records advertise the mail servers responsible for receiving email for your domain. Multiple MX records can exist with different priorities for failover.
How the MX record works
Lower priority = preferred. SMTP senders try MX records in ascending priority order. The most common email-deliverability bug we see is an MX pointing to a CNAME, which is illegal per RFC 2181. Always point MX records directly at a hostname that has A/AAAA records. An MX record check across global resolvers confirms every sending mail server worldwide sees the same mail routing.
Example MX record
example.com. 3600 IN MX 10 mail.example.com.Check a MX record live
Run the multi-resolver probe → and confirm propagation of your MX record across 12 global resolvers in real time.
Reference
Spec: RFC 1035, RFC 5321.
MX record FAQ
How do I check an MX record? →
Run a probe in dnsprobe and we look up the MX records from 12 global resolvers, showing each mail server and its priority so you can confirm email routing is consistent worldwide.
What does MX priority mean? →
MX priority (also called preference) controls order: lower numbers are tried first. Senders fall through to higher-numbered MX records only if the preferred mail servers are unreachable.
Why is my email not being delivered? →
Common MX faults are a missing MX record, an MX pointing at a CNAME (forbidden by RFC 2181), or an MX target with no A/AAAA record. A global MX check quickly isolates which resolvers see the wrong answer.