MX Lookup

Lists a domain’s MX records — the mail servers that receive email for the domain, in priority order.

Try it: sendlucid.com/mx-lookup

What you give it

A domain.

What it checks

• The domain’s MX records and their priority values (lower = preferred).
• Warns if there are no MX records (the domain can’t receive mail) or only one (no redundancy).

Why it matters

MX records are how the world delivers mail to you, and they’re a basic signal that a domain is a legitimate, configured mail domain. The full deliverability test includes an MX check as part of authentication.

How to read it

Most well-run domains have two or more MX records pointing at their mail provider. No records means inbound mail will bounce; a single record means an outage takes you fully offline.