All tools
Verification & PlanningA free tool by NullFortis
Email Verifier
Live mailbox check (best-effort)
What is it?
A live check of whether a specific mailbox actually exists and can receive mail, by talking directly to the recipient's real mail server — the same technique commercial list-verification tools use. No message is ever actually sent.
Why it matters
Sending to addresses that don't exist hurts your own sender reputation — bounce rate is one of the strongest negative signals mailbox providers track — and wastes send volume.
Impact if ignored
A high bounce rate from an unverified list can get your sending domain or IP flagged, hurting deliverability for every future email, not just the bad addresses.
Common use cases
- Clean an old contact list before a campaign
- Double-check a single important address before a one-off send
- Catch a typo in a signup form