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Who sends email for this domain?

We read the public evidence (MX records, every SPF include, and DKIM keys at the selectors big providers use) and list the mailbox host and every sending service behind a domain.

01 Where the evidence comes from

Three records give it away.

A domain has to tell the world who handles its mail, or receivers won't trust it. That makes the answer public, for anyone who knows where to look.

MX records

Where mail to the domain is delivered: the mailbox provider, or a security gateway in front of it.

SPF includes

Every service allowed to send as the domain. We unroll nested includes, because branded includes often wrap the real provider.

DKIM selectors

Signing keys published at provider-specific names (google, selector1, s1, k1…). A key delegated to a provider's domain is near-certain evidence.

02 Questions

Common questions.

Something else? Write to us — a real person answers, usually the same day.

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How accurate is this?+

Every provider listed comes with the record that matched, so you can judge it yourself. What it can't see: services that sign with selectors we can't guess, or that send from their own domain rather than yours.

Why does it list a service we stopped using?+

Because its include or DKIM key is still in your DNS. Leftover includes waste SPF lookups and still authorise that service to send as you, so remove them once you've moved off a tool.

Why check who sends for my domain?+

Before moving email providers, tightening DMARC or auditing who can send as you, you need the full list. Missing one service is how invoices or password resets start landing in spam after a change.

03 More free tools

Keep checking.

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