What is Valid Email Checker's accuracy guarantee?

Valid Email Checker stands behind a 99%+ accuracy guarantee across the verification engine. That number sits on the pricing page and the homepage, and it is the figure to keep in mind when you are evaluating VEC against alternatives. The guarantee has two components that are easy to confuse: an accuracy claim about the verdicts we return, and an auto-refund mechanic that ensures you never pay for an inconclusive lookup.

What 99%+ accuracy actually covers

When we return a definitive verdict — Safe, Risky, Invalid, Catch-All, Disposable, Role, Spam Trap, Disabled, Inbox Full — we are claiming that the verdict is correct at least 99 times out of 100. The figure is based on internal validation against ground-truth datasets and live sender-reputation outcomes from our customer base. It is not a marketing pull number. See how accurate is Valid Email Checker for the methodology.

The Unknown auto-refund is the other half

A verifier that returns a verdict on every address can hit 99% accuracy only by guessing on the edge cases — and guessing is exactly what produces bad sends. VEC instead returns Unknown when the engine cannot complete a verification with confidence, and refunds the credit when that happens. See what is VEC Unknown auto-refund. The practical guarantee is therefore: every verdict you pay for is 99%+ accurate, and you never pay for a non-verdict.

What the guarantee does not cover

• Sender behaviour after the verification. Even a 100% accurate verdict does not protect against bad list-acquisition habits, missing SPF/DKIM/DMARC, or sending at velocities your warmed pool cannot handle.
• Catch-all domains where the specific mailbox does not exist. A Catch-All verdict is correct that the domain takes all mail; whether the local part is a real human is unknowable from the outside. See are catch-all results eligible for refund.
• Provider-side weather. Temporary mail-server downtime that produces an Unknown is covered by the refund, not by the accuracy claim.

How to verify the guarantee yourself

The 200 welcome credits at signup are explicitly for this. Verify a list where you know the ground truth — your own active customers, your own personal addresses, a small batch of confirmed bounces from your ESP — and check the verdicts against reality. Most customers find the engine returns the expected answer on the addresses they can cross-check, and the small remainder fall into the Unknown bucket and refund themselves.