SpiderVerify: 99.2% Accuracy on 10M Emails

Email verification is table stakes for outbound. But accuracy claims are rarely backed by rigorous benchmarks. We decided to change that.

The Benchmark

We took 10 million real email addresses from agency campaigns (anonymized) and verified them against ZeroBounce, NeverBounce, and our own SpiderVerify engine.

Results

SpiderVerify achieved 99.2% accuracy — the highest in our benchmark. False positive rate was 0.3%, compared to 1.1% for the next best competitor.

How We Did It

Our secret is a multi-signal approach: MX record validation, SMTP handshake simulation, mailbox existence probing, and a proprietary deliverability model trained on 500M+ historical send outcomes.