AuthMode is a Boolean property that indicates if the SMTP server implementation requires authorization and/or authentication for new SMTP client connections. 

AuthMode is used in the command handler for the SMTP MAIL command to determine if the threaded client has identified itself to the server using the HELO or EHLO commands, and must be logged in prior to sending SMTP mail data. When AuthMode is True, the server will send the value in the Messages.NotLoggedIn protocol reply if the client connection is not logged in after the OnCommandAUTH event handler is triggered. 

The default value for AuthMode is False as assigned in the Create constructor. The server implementation can change the value in AuthMode prior to setting Active to True.

OnCommandAUTH TIdSMTPServerThread.HELO TIdSMTPServerThread.EHLO TIdSMTPServerThread.LoggedIn TIdSMTPMessages.NotLoggedIn