If you’re having problems with Outlook insisting on showing you a send/receive dialog even when you have checked the box to hide it in future the solution seems to be simple. Go to the View menu and make sure “Status Bar” is ticked at the bottom.
It appears that if there is no Status Bar to display progress, Outlook will display the Send/Receive dialog regardless of the preferences you’ve set.
If this doesn’t work for you, please leave a comment below.