Abstract: The present invention provides that while a mobile device is connected in an IDLE session on an IMAP mail server the mail client will be able to provide definite acknowledgements to the server as to whether it has received a particular response. If the client is disconnected involuntarily and upon reconnection it will be able to receive any responses that it may have missed during its disconnection and any response it had not acknowledged while connected. This will allow the client to thus avoid doing a deep synchronization after each reconnect. The present invention performs two main functions in order to avoid having the client perform deep synchronization. One, it clearly defines the set of information sent to the client during a reconnection, and two, it defines the behaviour that both the server and the client have during an involuntary loss of connection and the subsequent reconnection.