What is MX Record?

An MX record (short for Mail Exchanger) is a type of DNS record that tells the internet which mail servers should receive email for a domain (for example, where messages sent to @yourdomain.com should be delivered).

When someone sends an email to a recipient like [email protected], the sending mail server looks up the domain’s MX records to find the correct destination server(s) for delivery.

Why MX records matter

• They control inbound email routing: If your MX records are wrong or missing, emails sent to your domain may bounce or never arrive.
• They add reliability: You can publish more than one MX record so email can still be delivered if one server is unavailable.
• They affect replies and notifications: If you expect to receive replies (or system emails) on your domain, your MX records must point to the right mailbox provider.

How MX priority works (simple explanation)

MX records usually include a priority value (sometimes called “preference”). Lower numbers typically mean higher priority. Mail servers will try the highest-priority server first, then fall back to the next one if needed.

This is why many domains use a “primary” and a “backup” mail server.

MX record vs SPF, DKIM, and DMARC

MX records are about receiving email. Authentication records like SPF, DKIM, and DMARC are about proving legitimacy and protecting your domain from spoofing.

In other words:

• MX: where mail should be delivered (inbound routing)
• SPF/DKIM/DMARC: whether mail claiming to be from a domain is trustworthy

Common MX record issues

• No MX record: many servers will reject delivery or fall back to less reliable behavior.
• Wrong provider: MX points to an old mailbox service after a migration.
• Typos / formatting errors: a small mistake can break inbound delivery.
• Conflicting settings: multiple MX records are fine, but they should be intentional (correct priorities, valid hosts).

Related glossary terms

• DNS
• SMTP
• Message Transfer Agent (MTA)
• Deliverability
• SPF