Emails that have been "pushed" by the server should "pop in" and/or generate a notification. Observed in 4:4.5~20100910.1174804-1maemo2.1174786 .
New mail notifications have been implemented for WinCE in revision 1202330.
New mail notifications are shown correctly on WinCE, even with imap idle with a max delay of 30 seconds. So verified.