A message delivery server system for delivery of electronic content to a receiving client, comprises: a data storage for storing electronic content, a connection unit for maintaining a connection with the receiving client, and a connection establishment unit for allowing a receiving client to establish a connection with the server. The connection establishment unit comprises a definition unit for placing one or more connection definitions relating to the connection in an entity that is independent of any actual connection socket used for the session. The definition unit can be use to establish additional sockets to maintain the session and the definitions within can be used to find the best way to download media to the receiving client.