For those who have installed/planning to install Microsoft Office 2007 SP2 (Vista or XP):
One of the changes in this MS release causes some messages to show as From: "unknown" in the account's Sent folder for messages sent in Outlook. (It does not affect the recipient.)
The support portal now contains an updated ZimbraOlkConnector-5.0.16_GA_2922_5.0.2990.16.msi to address Bug 37146 - Sender shows as "unknown" after applying Outlook 2007 SP2 Hotfix (This is different than the connector that ships with 5.0.16)
ZimbraOlkConnector-5.0.16_GA_2923_5.0.2992.16.msi contains fixes for:
Bug 7146 - Sender shows as "unknown" after applying Outlook 2007 SP2 Hotfix
Bug 37941 - 'Microsoft Office Outlook Stopped working' message when clicked on Sharing tab of Boss.
Bug 36880 - Opening sharing tab crashes outlook