Status responses such as OK, NO, BAD, BYE, and so on are used to signal why any IMAP command between the client and the server failed. Each IMAP command is associated with OK, NO, and BAD status responses, with additional details specific to the command. These status responses may be tagged or untagged, carrying additional details.

For example, the IMAP command DELETE is associated with response codes OK, NO, and BAD. The status response of OK indicates that the delete command is successful. The IMAP command LOGIN is associated with a response code of NO which will carry additional details such as an invalid username or password; this signals that the login attempt was a failure:

The use of imap.request will filter all the IMAP COMMAND messages from client to server. If we know the specific command, the filter can be further granulized using imap.request.command == "<>":

By using imap.response, we can filter all the IMAP response status messages from server to client. Imap.response.status ==<> can be used to filter by response status, such as OK, NO, or BAD.