Tosh
In Outlook click File and see if Work offline if ticked. If it is then untick it (toggle).
In Options/mail set up there is a box send immediately when connected - That should be ticked.
In my own set up I have the first two boxes ticked under "Settings for group all accounts" and have not selected anything under "when outlook is offline"
For a neat job use kenhughes suggestion
Good luck
MC