Description
bool 
imap_ping ( resource imap_stream)
  
     Returns TRUE if the stream is still alive, FALSE otherwise.
    
     imap_ping() function pings the stream to see
     it is still active. It may discover new mail; this is the
     preferred method for a periodic "new mail check" as well as a
     "keep alive" for servers which have inactivity timeout.
     (As PHP scripts do not tend to run that long, I can hardly
     imagine that this function will be useful to anyone.)