MX Lookup
Check the mail exchange (MX) records for any domain to see which mail servers receive email for it.
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How to use this calculator
- 1
Enter the domain name whose mail servers you want to look up.
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Click "Check Now" to query MX records.
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Results show all mail servers sorted by priority (lower = higher priority).
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The lowest-priority server is tried first for email delivery.
Frequently asked questions
What is an MX record?
An MX (Mail Exchange) record specifies the mail server responsible for accepting email for a domain. Each MX record has a priority number — lower numbers are tried first. Multiple MX records provide redundancy.
Why do MX records have priorities?
Priority lets you designate a primary mail server and fallback servers. If the primary (lowest number, e.g. priority 10) is unavailable, sending servers will try the next priority (e.g. 20), ensuring email is not lost.
I set up Google Workspace — which MX records should I see?
Google Workspace MX records point to aspmx.l.google.com (priority 1) with four backup servers (alt1–alt4.aspmx.l.google.com at priorities 5, 10, 20, 30).
My domain has no MX records — what happens to email?
Without MX records, some senders will attempt to deliver email directly to the A record of the domain. Most will treat this as undeliverable. You should add MX records if your domain receives email.
MX Lookup — Find mail servers for any domain
How email routing works
When someone sends you an email, their mail server performs an MX lookup for your domain. It then connects to the highest-priority MX server returned and delivers the message via SMTP. If that server is unreachable, it tries the next priority.
Common MX configurations
Google Workspace uses aspmx.l.google.com. Microsoft 365 uses your-domain.mail.protection.outlook.com. Zoho Mail, Proton Mail, FastMail, and others each have their own MX record patterns. You can identify a domain's email provider just by looking at its MX records.
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