# Errors

When interacting with the **Mailzeet API**, it is important to understand the HTTP response codes used to indicate the success or failure of requests. This section provides a summary of these codes and their meanings in our context.

### Summary

* Codes in the **2XX** range mean that the API request was processed successfully.
* Codes in the **4XX** range mean that something was wrong with the data that you sent. For example, you might have missed some required parameters/headers, or you might be using the wrong API credentials.
* Codes in the **5XX** range indicate an error in processing on our end.

### Common HTTP Codes

| HTTP Code | Meaning                                                                                                                                      |
| --------- | -------------------------------------------------------------------------------------------------------------------------------------------- |
| 200       | OK - The request was successful.                                                                                                             |
| 201       | Created - The request was successful, and a resource was created.                                                                            |
| 400       | Bad Request - The request was invalid or cannot be processed.                                                                                |
| 401       | Unauthorized - Authentication credentials were missing or incorrect.                                                                         |
| 403       | Forbidden - The request is understood, but it has been refused.                                                                              |
| 404       | Not Found - The requested resource could not be found.                                                                                       |
| 500       | Internal Server Error - An error occurred on the server. In this case, feel free to retry or contact [support](mailto:support@mailzeet.com). |
| 503       | Service Unavailable - The server is currently unable to handle the request.                                                                  |

Understanding these response codes will help you effectively handle both successful operations and errors when interacting with the **Mailzeet API**.