Free tool
Email provider lookup
Enter a domain or an email address to see which provider hosts its mail. We read the domain's MX records and use its SPF record as a hint. Free, no signup.
Results for
github.com
Looks good
Mail is hosted by Microsoft 365
The MX records of github.com point at github-com.mail.protection.outlook.com, which belongs to Microsoft 365.
OK
| Priority | Mail server |
|---|---|
| 0 | github-com. |
Moving away from Microsoft 365? The migration planner lists the steps in order. Plan a move from Microsoft 365
How the lookup finds the provider
Mail for a domain goes wherever its MX records point. The lookup reads those records and matches each mail server's host name against the hosts that providers publish in their own setup guides. Google Workspace, for example, tells customers to publish smtp.google.com, and Microsoft 365 uses a host under mail.protection.outlook.com.
It recognizes Google Workspace, Microsoft 365, Shipmail, Zoho Mail, Proton Mail, Fastmail, iCloud Mail, IONOS, OVHcloud, Namecheap Private Email, Infomaniak, Gandi, mailbox.org, Yandex 360, Rackspace Email, Hostinger Email, Amazon WorkMail or SES, Migadu, Cloudflare Email Routing, ImprovMX, GoDaddy Professional Email, Mimecast, Proofpoint Essentials, Cisco Secure Email and Barracuda Email Gateway Defense. Each one is matched from the MX hosts on the provider's own documentation page, and we leave a provider out when we cannot find that page.
Why SPF is only a hint
An SPF record lists the services allowed to send mail as the domain, not where its inboxes are. A company on Microsoft 365 that sends newsletters through another service includes both. So the lookup shows SPF includes as a hint, and the MX records always decide the answer.
SPF helps most when the MX host is a filtering gateway or a server named after the domain. If the record includes one mail provider, that provider may host the mailboxes behind the gateway, but only the provider's own settings can confirm it.
When the answer is not a provider
A host such as mail.example.com belongs to the domain itself. That can be a server the company runs, or a provider set up behind a custom name. A forwarding service such as Cloudflare Email Routing receives the mail and passes it on, so the inbox lives somewhere else.
A null MX record (priority 0, host ".") says the domain takes no mail at all. No MX records at all usually means mail was never set up for the domain.
Moving to another provider
When the lookup names a provider the migration planner covers, it links to the plan for that provider: what to export or import, when to change the MX records, and when to close the old account. Check the domain again with the DNS propagation checker after you change the records.
How can I tell who hosts a domain's email?
Look up the domain's MX records. The host names they point at belong to the mail provider, for example smtp.google.com for Google Workspace. This tool does the lookup and names the provider for you.
Can I find the provider from an email address?
Yes. Enter the address and the tool checks the part after the @. It reads public DNS only, so it does not contact the mailbox or tell anyone you looked.
Why does the result say the host is not in the provider list?
The MX records point at a server we cannot match to a provider's published hosts. It can be a smaller host, a filtering gateway in front of the real provider, or the company's own server. The SPF hint often fills the gap.
Is the domain registrar the same as the email provider?
Not necessarily. The registrar sells the domain name, and the DNS host serves its records. The email provider is whoever the MX records point at, which can be a third company.
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