Hi guys, wondering if anyone can enlighten me on this error: Expected response code 250 but got code "421", with message "421 4.4.2 Message submission rate for this client has exceeded the configured limit A staff gets this whenever he wants to bulk update (close) tickets. Was of the opinion there was a limit on the mail account used by kayako however, the ms exchange guy says there's no limit. I've checked under settings>Email settings to find where i might increase this "message submission rate" but can't see anything related. IS this error popping up because of an incorrect setting on the application server or on the exchange server? Anybody with some idea, please help. Thanks. Remi.