Every common pattern for a name is tested against the company's own mail server. Accepted means the mailbox exists. Results are live, private, and never stored.
One person per line as first last domain.com. Middle names, accents and pasted URLs are handled.
Accepted mailbox exists · Rejected mailbox does not exist · Catch-All server accepts every address, cannot be verified · Limited over quota or rate limited · Greylisted server asked us to retry later · No MX / MX Error no mail server or server error · Timeout no response · SPAM Block server refused the check · Skipped not tested, a match was already found · Blocked port 25 closed where the checker runs.