I have very occasionally experienced e-mail stuck in the outbox with every version of Outlook used (currently 2007 and about to move to 2010). Usually closing and restarting Outlook (not the PC) solves it so given the infrequency I have never dug in to "why?".
I do though use a different way of reducing the chance of inadvertently sending e-mail that I implemented many years ago as a result of accidentally pressing the keyboard shortcut for "send" a few times when speed typing (I pick up a furious pace when I'm in full flow)
I simply include a guff e-mail address amongst the recipients. ddddddddddddddddddddd or fffffffffffff or tttttttttttttt or whatever key I choose to press. This causes Outlook to stop and ask what I want to do as it doesn't recognize the address.
Nice and simple.
