We cannot promise that any of these will help, but if your Outlook mail client hangs on send/receive, beside closing and re-opening Outlook (which works but is annoying if the problem repeats with any significant frequency), here are three things to try:
1. Go to Control Panel/Programs/Outlook and right-click and choose Repair.
2. Disable any Add-Ins.
3. One of the common reasons for auto Send/Receive to stop working has to do with a group Send/Receive group in Outlook. Here’s how to fix the problem with the corrupt Send/Receive group.