I have had a look in the forums, found this thread
Im having basically this issue but instead of the message sitting in the outbox it goes to the sent items but instead of sending just once like intended it sends thousands of times ( see attachment ).
We can also see it in the zimbra.log, over and over again to the same recipient, so it may not be an outlook connector issue but an issue on the server but can't be sure as its only 1 windows 7 workstation running office 2010 with the latest outlook connector out of 12 others that dont have this issue.
We are running Release 7.1.1_GA_3196.UBUNTU10_64 UBUNTU10_64 NETWORK edition
If anyone can assist with this issue would be greatly appreciated, the client is getting some very nasty phone calls when this happens.
Thanks in advance!