What is Valid Email Checker's Unknown auto-refund?

Valid Email Checker treats Unknown results as a no-charge outcome. When the verification engine cannot return a definitive answer for an address — usually because a destination mail server timed out, a greylisting policy blocked the SMTP probe, or an anti-spam layer dropped the handshake — the credit you spent on that lookup comes straight back into your Pay-As-You-Go bucket. The behaviour is encoded in our refund-credits edge function and runs as part of the same job that writes the verification result, so the refund happens in the same fraction of a second the Unknown status appears in your dashboard.

Why we made the call to refund

An Unknown result is not the same as a successful verification. You did not learn whether the mailbox accepts mail, so charging you for that lookup would be charging for incomplete information. We absorb the upstream provider cost and return the credit to you. This is the most important practical guarantee VEC offers, and it is what lets new accounts experiment freely without burning down their 200 welcome credits on transient SMTP weirdness. The cost on our end is real — we still pay the upstream provider for every probe, whether it succeeded or not — but we would rather eat that cost than ship a billing model that punishes customers for the moodiness of the wider mail-server ecosystem.

Which bucket the refund lands in

Refunds always land in the PAYG bucket via the atomic_refund_credits RPC. Even if the original deduction came from your Monthly subscription bucket, the credit returns to PAYG because PAYG never expires — pushing it back into a soon-to-reset Monthly bucket would be unfair. See what is the PAYG bucket in Credits History for the bucket model.

What counts as Unknown

The Unknown status fires for any address where the engine cannot make a confident determination — SMTP timeout, greylisting bounce, an anti-spam layer rejecting our probe, or a mail server that returned a temporary 4xx response that did not clear inside the retry window. See what does Unknown status mean for the full taxonomy. Every one of those outcomes routes through the same refund path, regardless of which provider tier or verification mode produced it.

How to confirm it ran

• Open Credits History from the sidebar.
• Filter by transaction type refund.
• You will see one +1 row per Unknown verification, with a description like "Credit refund: 1 credits" pointing at the original verification task.