Voice Mail Message Waiting Indicator (Exchange 2010) does not work

Problem: for the user Message Waiting Indicator does not work - does not get lighten up when the voice mail is left.

Resolution:

1. Make sure that Outlook is running in online mode (Not Cached Exchange Mode).  In online mode Outlook will say "Online with Microsoft Exchange" in the status bar, not "Connected with Microsoft Exchange".
2. Delete the Voice Mail search folder in Outlook.  This only deletes the search folder, not the messages.
3. Dial into Outlook Voice Access to access your old voicemails.  You need to enter the "voice mail" command, even if OVA says you have no new voicemails.  When you do this, EWS will recreate the Voice Mail search folder in Outlook.  Hang up.
4. Reconfigure Outlook to use Cached Exchange Mode again and restart Outlook.  Since the OST header still matches the mailbox database header, Outlook will use the same OST and will resync your emails quickly and easily.

Reference article: http://www.expta.com/2012/01/how-to-reset-exchange-2010-mwi.html