Unable to send via Outlook for Mac 2011 - but to just one address
I use Outlook for Mac in our corporate environment. I am unable to send to just one user. The e-mail address is valid and Outlook generates the least helpful error message of all time "An unknown error has occurred in Outlook." The problem started with a meeting invitation response.
All of the information I have been able to dig up refers to a general problem sending, not sending to one particular address.
OS X Mountain Lion (10.8.2)