Windows Mail won’t let me in because it’s tryng to send two emails with probable bad addresses.

I have two messages in my outbox that can't be sent for some reason I am not aware of.  When I try to sign in to Windows live I get the program attempting to send the messages and it will not let me in.  All I need to do is delete the messages as it must be a bad email address but I can't find where they are stored.  I can not access windows live mail because of this.