How SMTP Email Verification Works
See how SMTP recipient probes use RCPT TO, interpret 2xx, 4xx, and 5xx replies, detect catch-all domains, and preserve unknown results.
See how SMTP recipient probes use RCPT TO, interpret 2xx, 4xx, and 5xx replies, detect catch-all domains, and preserve unknown results.
Learn how email verification checks syntax, mail routing, provider risk, SMTP responses, and catch-all domains, plus what each result really means.