What the verdicts mean
Valid, Bounce, Catch-all and Unknown explained, plus the flags for role addresses, disposable inboxes and personal email providers.
Every check ends in one of four verdicts. The app, the API, MCP and list downloads all use the same four. In the app, an invalid address is labeled Bounce. In the API and in list downloads it appears as invalid.
The four verdicts
| In the app | In the API and downloads | What it means |
|---|---|---|
| Valid | valid | The mailbox exists and accepts mail. |
| Bounce | invalid | Sending here would bounce. |
| Catch-all | catch_all | The domain accepts every address, so a regular check can't tell if this one is real. |
| Unknown | unknown | The mail server gave no clear answer. Always free. |
Bounce
An address is marked Bounce for any of these reasons:
- The mail server rejected the mailbox.
- The mailbox is disabled.
- The mailbox is full.
- The domain has no mail server.
- The address has bad syntax.
The result card tells you which one applied. Bad syntax and no mail server are free. A rejected, disabled or full mailbox is a real answer from a live check and uses 1 credit.
Catch-all
Some domains say yes to every address, even a made-up one. The catch-all test in each result shows whether a made-up address at the same domain was accepted. When that made-up address is accepted too, the yes for your address proves nothing, so the verdict is Catch-all. If you need a firmer answer, you can run an optional catch-all check.
Unknown
The server did not give a clear answer. Common causes are a timeout, a block, or greylisting, where a server asks senders to come back later. Unknown results never use credits.
Flags
Alongside the verdict, a result can carry flags that help you decide what to do with an address:
- Role address: a shared inbox such as
info@orsales@, shown as Shared inbox (role address). - Disposable inbox: a throwaway address.
- Personal email provider: a free or personal email service rather than a company domain.
- Mailbox full and Disabled: shown as the mailbox answer, and both lead to a Bounce verdict.
Related
Last updated November 6, 2026