Bouncebuster
How it works

Real SMTP verification, no guesswork

Bouncebuster checks each address the way a mail server would — but without ever delivering a message. Here’s the full pipeline.

1

Syntax & normalization

We normalize the address and reject malformed syntax up front, following the same rules mail servers use.

2

MX lookup

We resolve the domain’s mail exchangers. No mail servers means mail can’t be delivered — the address is invalid.

3

Live SMTP probe

From dedicated, reputation-managed IPs we open an SMTP conversation and ask whether the mailbox exists — without ever sending an email.

4

Catch-all detection

We probe a random address on the domain. If the server accepts anything, we mark the domain catch-all so you aren’t misled.

5

Disposable & role checks

We flag throwaway/disposable providers and role-based mailboxes (info@, support@) so you can decide what to keep.

What you get back

Valid

The mailbox exists and accepts mail. Safe to send.

Invalid

Bad syntax, no mail server, or the mailbox does not exist. Remove these.

Catch-all

The domain accepts everything, so we cannot confirm the individual mailbox.

Disposable

Temporary / throwaway inboxes. Usually worth removing.

Unknown

The server wouldn't give a clear answer. Never charged to your account.