MX Lookup

MX Lookup shows the mail servers that receive email for a domain, in priority order, with the IP address of each one. MX (mail exchanger) records are what every sending mail server looks up to find where to deliver a message, so if they are missing or wrong, email to that domain bounces or disappears.

How to use MX Lookup

1. Enter a domain such as example.com. A full URL or a leading www. is cleaned up automatically.
2. Click the lookup button.
3. Read the mail servers from the lowest priority number (tried first) to the highest (backups). Use the share menu to copy a link to the result or save it as a report.

How to read the result

• Priority: a lower number means a preferred server. Senders try the lowest first and fall back to higher numbers if it does not answer. Servers with the same number share the load.
• Mail server: the hostname that accepts mail for the domain.
• IP address: the IPv4 address that hostname resolves to. A mail server with no IP address cannot receive mail.

Recognising common email providers

• Google Workspace: smtp.google.com, or the older set aspmx.l.google.com with alt1 to alt4 backups.
• Microsoft 365: yourdomain-com.mail.protection.outlook.com.
• Zoho Mail: mx.zoho.com, mx2.zoho.com and mx3.zoho.com.
• Hosting companies often use a mail.yourdomain.com or mx1.hostname style name.

When it comes in handy

• Checking that a move to Google Workspace or Microsoft 365 is complete, so mail no longer goes to the old host.
• Finding out why emails to a domain bounce with "no mail server" or "host not found" errors.
• Seeing which email provider a company uses.
• Verifying that an email address's domain can receive mail before sending to it.

MX records only cover receiving. For delivery to inboxes rather than spam folders, also check the domain's SPF, DKIM and DMARC records with the SPF, DKIM & DMARC Checker, and the mail server's reverse DNS with IP to Hostname.

Frequently asked questions