Anyone seen this before? You'll get it if you try to click "e-mail" in the standard tool bar of an office app (or other applications with similar function), or coosing mail recipient in the "send to" menu. MS says this: http://support.microsoft.com/?scid=kb;en-us;829061&spid=2520&sid=139 I checked some users having this problem and they have no com add-in's installed. I'm not sure what else to check. The option of "starting outlook" is not good for the way these people use Citrix. It appears that MS never intends to fix it based on this KB article. Any suggestions on what else to try? It only effects some users and not all users, which is unusual.