MX Record Lookup Tool

What MX Records Do

Mail Exchange (MX) records are the DNS records that determine where email for your domain is delivered. Every time someone sends mail to user@yourdomain.com, their mail server performs an MX lookup, retrieves the list of mail servers authorised to receive mail for your domain, and attempts delivery in priority order — lowest priority number first.

A domain can have multiple MX records for redundancy. If the primary mail server (lowest priority number) is unavailable, the sending server tries the next one. Most email providers supply between one and five MX records as part of their setup instructions.

How to Use This Tool

Enter your domain name and click Look Up. The tool returns your full set of MX records including the mail server hostname and priority value for each. Compare the results against your email provider's required configuration to confirm everything is set up correctly.

MX Records for Common Providers

• Google Workspace: Five records — ASPMX.L.GOOGLE.COM (priority 1), ALT1 and ALT2 (priority 5), ALT3 and ALT4 (priority 10).
• Microsoft 365: One record — [your-domain-hash].mail.protection.outlook.com at priority 0.
• Zoho Mail: Two records — mx.zoho.com (priority 10), mx2.zoho.com (priority 20).
• Proton Mail: Two records — mail.protonmail.ch (priority 10), mailsec.protonmail.ch (priority 20).

Common MX Record Mistakes

• Pointing to a CNAME: The DNS specification (RFC 2821) forbids MX records from pointing to CNAME aliases. Use only hostnames that have A or AAAA records.
• Pointing to an IP address: MX records must always point to hostnames, never directly to IP addresses.
• Duplicate priorities on primary and backup: Giving your primary and backup servers the same priority number makes delivery unpredictable. Use distinct values (10, 20, 30) to control failover order explicitly.
• Missing records after a domain transfer: Registrar transfers can wipe DNS records if you rely on registrar-hosted DNS. Export your full DNS zone before initiating any transfer.

When MX Lookup Is Not Enough

MX records confirm where email should be delivered but don't guarantee deliverability. If your email is being rejected or going to spam, check your TXT records for SPF, DKIM, and DMARC configuration using the TXT record checker. A valid MX record with missing or broken SPF will still result in delivery failures at many receiving servers.