IMAP server not working?

Did you give restarting it a try in WHM?

Restart Services/IMAP Server

 

imap on cPanel actually runs through xinetd. You could try restarting xinetd whilest monitoring the /var/log/messages file and look for errors. To restart xinetd:

/etc/init.d/xinetd restart

The file xinetd uses should be /etc/xinet.d/cpimap and contain:

Code:

# default: off
# description: imapd
service imap
{
        socket_type             = stream
        wait                    = no
        user                    = root
        server                  = /usr/sbin/imapd
        disable                 = no
}

Make sure that in your file disable isn't set to yes.

Lastly, you haven't installed a firewall recently have you and forgotten to open port 143?

You can check whether imap is actually running on the server with:

netstat -lpn | grep 143