Email verification, built around the one problem most verifiers get wrong.

Most email verifiers do a regex check, a DNS lookup, and call it a day. That works on roughly two-thirds of the addresses they see and fails on the rest — specifically on the Google Workspace and Microsoft 365 mailboxes that accept every probe (because anti- enumeration accepts every RCPT TO and lets the rejection happen later, post-send). A surface-level verifier reads those as Valid · 95% confidence. Then the real send goes out and the bounce hits the sender's domain reputation.

KillBounce was built specifically to get those right. The probe is three layers — syntax, DNS/MX, and a live in-session SMTP check — with explicit catch-all detection and a category for "we can't tell without sending, here's the risk score." Nothing is labelled valid unless the evidence is there.

Outbound and lifecycle operators cleaning lists before a send. Product teams validating signup forms in real time. RevOps and agencies running list hygiene as part of a recurring workflow. Anyone who's paid a monthly verifier subscription and watched the bounce rate climb anyway.

It's not for everyone. Teams that want a managed deliverability console with email warmup and inbox placement testing should look elsewhere. KillBounce does one thing: tell you whether an address is real, and refund the credit when it's wrong.