If Outlook opens but you are not receiving any new Emails, this may be the result of Outlook inadvertently enabling Work Offline mode.
Check the bottom bar of your Outlook. If you see "Working Offline", then this article should resolve this issue.
To fix this:
- Launch Outlook
- Click on the Send / Receive tab
- Click the Work Offline button to deselect it (Button should not have a gray outline around it)