A user has a problem: he often sends large messages and they often get stuck in the Outbox. He forgets to check the Outbox and would like a warning message when messages won't send.
You will not get a dialog that says 'hey, something is wrong and the message didn't send' but you can get some warnings, plus the Outbox shows the message count. Add it to your Favorites section (Outlook 2007/2010) so you can see it easier.
There is the possibility of two warnings about messages in the Outbox:
When you close outlook with unsent messages: (This does not work in Outlook 2010 RTM, but works in all older versions and Outlook 2010 SP1.)
When there is a send/receive failure: In Outlook 2010, click Show progress on the Send/Receive ribbon then untick the 'don't show this dialog box' option. The dialog will come up with each send/receive and if there is an error, you'll see it on the error tab. In older versions, its on the Tools, Send & Receive menu, look for the Show Progress command.
Published June 3, 2011. Last updated on May 5, 2017.