By checking what is observable from outside: whether the address parses, whether the domain publishes mail servers, whether the provider is a disposable one, whether the local part is a role address, and whether the domain accepts everything sent to it. No message is ever sent to the address, which is why the result is a confidence score rather than a guarantee.

Free, and no account is needed. It is metered rather than unlimited: 5 validations and 5 finds a day. Signing in does not reduce that, and paid plans raise it.

Yes, up to 100 addresses in one batch, one per line, returned as a table you can export. Larger jobs are what the REST endpoint is for.

Yes. Give a first name, a last name and a domain, and the common address patterns are generated and then verified, so what comes back has been checked rather than guessed.

A domain configured to accept mail sent to any address at it, existing or not. That means an outside check cannot confirm one specific mailbox, so the result is reported as catch-all rather than valid. It is information, not a failure: mail will very likely be accepted, but you cannot prove the mailbox exists.

Yes, and it needs no key: POST an address to /api/v1/email/validate, or a name and domain to /api/v1/email/discover. CORS is open so it works from a browser. There is also an MCP server, so an assistant can call it directly.

Yes. Switch the tool to LinkedIn, or use the LinkedIn email finder page: paste any profile URL and get the verified business email.

Validation history is stored in your account only. We never sell data and we don't share individual email validations with third parties.