SMTPing Email Verifier

SMTPing verifies email addresses directly from Claude, so you can clean a list or check a single contact before you send.

Every address gets one of 13 verdicts, grouped in 3 bands:

• safe: send (valid, alias)
• avoid: remove (invalid, spamtrap, disposable, blacklisted, complainer, spambot, inbox full)
• judgement: your call (catch-all, role, unknown)

What it catches that a basic valid/invalid check keeps:

• 150M known spamtraps
• 70M complainers who report mail as spam
• 2M+ spambots and bot clickers
• 3,500+ disposable domains, monitored daily
• 70M+ addresses listed on 80+ blocklists

Tools:

• verify_email: one address, median 58 ms (1 credit)
• verify_list: up to 100,000 addresses as one deduplicated bulk job (1 credit per unique address)
• get_bulk_job: progress and results of a bulk job (free)
• check_threat: one lookup in the spamtrap, disposable, spambot or complainer list (1 credit)
• get_credits: remaining balance and plan (free)

Unknown results are never charged. Every account gets 25 free credits per day. Sign in once with your SMTPing API key on the SMTPing consent page; the key is encrypted inside the access token and never stored by the server.