221 Terminates the session. OK Initiates the authentication process. All commands issued to an IMAP4 server must be prefixed with a command identifier. This identifier can be interpreted by the client in order to keep track of command and response pairs. A NO response is given when a command is denied.
Authentication requires the first two commands listed.
Supplies password for authentication. QUIT 205 Terminates the session. The second troubleshooting method applies only to Exchange Server. Exchange Server performs protocol logging for most of its protocols. With protocol logging turned on for the protocol in question, the actual conversation between hosts is transcribed to a text file.