# Email certainty levels

> What the certainty levels of the Icypeas API mean (ultra_sure, very_sure, probable, undeliverable, not_found) and which emails are safe to send to.

Source: https://api-doc.icypeas.com/certainties


Every email returned by Icypeas comes with a `certainty`: how sure we are that the address exists and will receive your message.

| `certainty` | Applies to | Meaning | Send? |
| --- | --- | --- | --- |
| `ultra_sure` / `very_sure` | All searches | 99% confidence. Expected bounce rate below 1%. | ✅ Yes |
| `probable` | All searches | 95% confidence. Expected bounce rate below 5%. | 👍 Usually |
| `undeliverable` | Email verification | The address does not exist. | ❌ No |
| `not_found` | Email search, domain search | No email was found for this person or domain. | Nothing to send |
| `not_found` | Email verification | We can't tell whether the address exists (for example the server accepts everything). | ⚠️ At your own risk |

Where to find it in a result:

```json
"results": {
  "emails": [
    {
      "email": "pierre.landoin@icypeas.com",
      "certainty": "ultra_sure",
      "mxProvider": "google",
      "mxRecords": ["google.com"]
    }
  ]
}
```

`mxProvider` tells you who hosts the mailbox. See [MX providers](https://api-doc.icypeas.com/mx-providers).