---
title: "What is MX record (Mail Exchanger record)?"
url: "https://lookvalid.com/glossary/mx-record.md"
canonical_url: "https://lookvalid.com/glossary/mx-record"
last_updated: "2026-10-18"
type: "conceptual"
summary: "An MX record is a DNS entry that names the servers which accept email for a domain, each with a priority number."
related: ["https://lookvalid.com/glossary/smtp-verification.md", "https://lookvalid.com/glossary/spf.md", "https://lookvalid.com/glossary/catch-all.md", "https://lookvalid.com/products/email-domain-check.md"]
---

# What is MX record (Mail Exchanger record)?

An MX record is a DNS entry that names the servers which accept email for a domain, each with a priority number.

A sending server looks up the MX records for the part after the @ and tries the lowest priority number first. If a domain has none, senders fall back to the domain's address record, and a domain can publish a "null MX" to say it accepts no mail at all.

A domain with no working way to receive mail cannot have a real mailbox, which is why an MX lookup is the cheapest useful check on an email address.

## Related

- [What is SMTP verification?](https://lookvalid.com/glossary/smtp-verification.md)
- [What is SPF (Sender Policy Framework)?](https://lookvalid.com/glossary/spf.md)
- [What is Catch-all?](https://lookvalid.com/glossary/catch-all.md)
- [Email Domain Check API](https://lookvalid.com/products/email-domain-check.md)