I have Exchange 2007 SP1 running on Windows server 2008. Suddenly it stopped responding to IMAP connections. I could telnet to the port to open a connection, but mail clients would just hang. netstat reveiled quite a few CLOSE_WAIT connections I tried to restart the IMAP service but it wouldn't restart. I ended up restarting the server and now it's responding nicely. I'm going to look through the logs right now, but I'd like to get others' input. Any thoughts or comments would be appreciated.