MX Record Lookup: Check a Domain's Mail Servers
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MX Record Lookup

Look up the mail exchange (MX) records for any domain. See which servers handle email and identify the email provider.

What Are MX Records?

MX (Mail Exchange) records are DNS records that specify which servers handle email for a domain. When someone sends an email to user@example.com, their mail server looks up the MX records for example.com to find where to deliver it.

MX Record Priority

Each MX record has a priority number (lower = higher priority). Mail servers try the highest-priority (lowest number) server first and fall back to others if it's unavailable.

The current Mailthentic result lists hosts in resolver order but does not display their numeric priorities. Use an authoritative DNS client when exact preference values are required.

Common Email Providers and Their MX Records

ProviderMX Pattern
Google Workspace / Gmailaspmx.l.google.com
Microsoft 365 / Outlook*.mail.protection.outlook.com
Yahoo*.am0.yahoodns.net
ProtonMailmail.protonmail.ch
Zohomx.zoho.com

Troubleshooting an MX check

No MX: confirm the root domain and compare authoritative DNS. SMTP standards permit A or AAAA fallback, but an explicit MX is clearer for a domain intended to receive mail.

Null MX: a preference 0 record with exchange . explicitly says the domain accepts no email. It differs from a missing record.

Invalid hostname: the target must be a hostname, not an IP address. Check for provider-token and DNS-field errors.

Several priorities: documented primary and backup hosts are normal. Remove old routes after a provider migration.

Recent change: recursive resolvers can retain the old answer until the previous TTL expires.

What MX cannot prove

An MX result shows where a domain routes inbound mail. It does not prove that an individual mailbox exists, that a message will be accepted, or that it will reach the inbox.

Read how to check MX records. Continue with the domain health checker, SPF, DKIM, DMARC, or the single email checker.

Need to verify email addresses on this domain?

MX is a domain-level signal. Check one address for additional DNS signals or create an account for the full workflow.