If Outlook was launched during a period of no connectivity by, default the program will switch to offline mode and might stay even when you get access to network connectivity. Please check to confirm you are not in Work Offline mode if you are not receiving/sending emails:
- Click on Send/Receive tab in the ribbon
- In the Preference section near the right-hand side of the program notice the Work Offline button. This toggle button clicks once to turn on or off - if it's shadowed outline it is on and the status bar at the bottom right reflects that you are Working Offline. Click once and shadow outline is gone and the status bar at the bottom right refects that you are connected to Microsoft Exchange.