Have the same issue here with clients upgraded to Outlook SP2. Our server has not been upgraded.
I can confirm that it doesn't occur on SP2 if ZCO is not installed. It also doesn't occur on ZCO 5.0.15 if Outlook SP2 is not installed. However, if both are installed, then emails sent from Outlook have the from address as "unknown".
Haven't tested Outlook SP2 with previous version of ZCO... |