Has your IMAP connection become slower since upgrading to Outlook 2010? Especially when switching folders? There is currently 1 hotfix available from Microsoft found here:


http://support.microsoft.com/kb/2459115




If the folder-switching performance is still slow after applying the hotfix, it could be caused by one of the reasons below:


Virus Scanner - Particularly applications like Active Scanning.

Add Ins - An add in could be causing it to perform slow.

Complex View - Try resetting back to default view.

Account Configuration Corruption - Remove the IMAP account, restart Outlook, then add the IMAP account again.