General error codes.
| Code | Description |
| Internal Errors | |
| 100 | Unable to create message raw file. |
| 101 | Message raw file was not found. |
| 102 | Invalid email address. |
| 103 | Creating and sending of message was cancelled. |
| 104 | Duplicate email address. |
| 105 | Email address in exclusion list. |
| 106 | Unable to find mail exchange server for a specified email address. |
| 107 | Mail exchange server for a specified email address was not found. |
| 108 | Socket disconnected. |
| External Errors | |