Definition

MX Record

Also known as: Mail Exchange Record

A DNS record that tells other servers which mail server is responsible for receiving email for a domain.

An MX (Mail Exchange) record is a DNS entry that names the server responsible for accepting email on behalf of a domain. When you send to [email protected], the sending server looks up example.com's MX records to find where to deliver the message. A domain can list several MX records with priorities for failover.

MX records are the first real verification signal beyond syntax: if a domain has no MX records (and no usable fallback A record), it cannot receive email at all, so every address there is invalid. This check is fast and definitive.

A valid MX record only proves the domain can receive mail, not that a specific mailbox exists — that requires an SMTP probe.

Related terms

See it in action

Check any address against BounceShift's multi-layer engine — syntax, MX, disposable, and role checks free, with full SMTP verification on signup.