What is the difference between a client issuing the commands needed to move to the Selected state and then waiting with an open recv() vs IDLE. Is it an informal way of communicating to the server that the client has a pending recv()? Given rfc3501 Sec 5.3 it would seem the server would behave properly in either case.
The server often doesn't know whether the client is listening on its TCP socket. For example, when there is an IMAP proxy or TCP-level firewall between the two, the server cannot trust the advertised TCP window to indicate recv().
Arnt
