Is it possible to stop an already begun transmitting email from the outlook outbox?

I tried to send a huge file and its been trying to send for 13 hours now - but I cant delete it becasue it says its already begun transmitting.|||Press Ctrl+Alt+Delete to pop up the windows task manager, then click on the "processes" tab. Find the appropriate tab for your browser, and click on "End Process". This will safely shut down your browser.