To troubleshoot this, you can reset the mail profile or move to working online from working offline. To do this, follow the steps below:
Reset the mail profile
Ensure that Outlook is closed.
Click the Windows icon in the bottom left of your screen.
Type in Control Panel.
Click on Mail.
Click on Show Profiles.
Remove the current profile.
Click Add.
Name the profile.
Your account information should automatically populate.
Click Next.
Click Finish.
This will now have reset your mail profile. Once you re-open Outlook, it may take up to 10 minutes for all emails to refresh and re-appear.
Move to working online from working offline
Identify if you're working offline by looking in the bottom right of outlook to see if it says Working Offline.
Click the Send and receive tab.
Click Work offline.
This will now remove the work offline status and allow emails to refresh.
If neither of the methods mentioned above work or if you have issues with this, please raise a new case online and reference the title of this article.