Quicksearch presents and delivers status codes for email messages in several parts of the system.
The codes used are:
| Code | Meaning |
| 0 | Incorrect or missing address |
| Codes below 1000 | Standard SMTP code based on the response from the receiving mail server. See SMTP standard for clear descriptions. 250 means the message has been received by the recipient server, all other codes mean the message has not been delivered yet. |
| 1001 | The recipient is on Quicksearch's block list. The most common reason is that the email address has repeatedly responded with a permanent error indicating the address is missing. If Quicksearch continues to send to the address, there is a high risk that our mail servers will be blocked for sending, so they are sorted out. There are also individual cases where email addresses have been blocked based on a request from the recipient. |
| 5900 | The receiving mail server cannot be reached. It is common if the domain does not exist at all, if there is no MX pointer to the domain, or if no mail server responds on the other side. This code comes after 10 repeated attempts to send to the address. |