Email Verifier

Bounces are a reputation problem

A hard bounce is not a wasted email, it is a mark against your sending domain. Mailbox providers treat a high bounce rate as evidence that a sender is working from a scraped or stale list, and they act on it by routing the rest of your mail to spam. Verification is the cheap step that keeps the expensive one from happening.

What a real check looks at

Syntax rules out the typos. A DNS and MX lookup rules out domains that cannot receive mail at all, which is most of what a list picks up as companies fold or rebrand. The mailbox check is the last layer: an SMTP conversation with the receiving server that stops short of delivering anything but asks whether that specific address would be accepted.

Catch all, role and disposable

Three categories deserve their own label rather than a pass or fail. Catch all servers accept everything, so nothing can be confirmed. Role addresses like info@ and sales@ usually reach a shared inbox and convert badly. Disposable addresses come from throwaway providers and are worth removing on sight.

When to re-verify

B2B lists decay at roughly two to three percent a month as people change jobs. A list verified six months ago is not a verified list. Re-checking before each campaign costs very little compared with the deliverability you lose by sending to it blind.