Exchange Online shared mailbox not syncing new emails in Outlook desktop

Hi Palmira Paerce

Thanks so much for posting your question on the Microsoft Q&A Forum.

Before we dive into troubleshooting, please make sure Outlook is fully updated by going to File > Office Account > Update Options > Update Now. If the issue persists after updating, run a repair using this guide: Repair Outlook - Microsoft Support.

If you’re using New Outlook for Windows, start by removing and re-adding the account:

1. Open Outlook.
2. Go to Settings > Accounts.
3. Remove the shared mailbox account.
4. Add it back again and restart Outlook.

If you’re using Classic Outlook, first try removing and re-adding the account. If the issue still persists, check your Cached Exchange Mode settings. You can refer to this guide: Cached Exchange Mode - Microsoft Support

If the problem continues for either version, create a new Outlook profile, re-add your account to the new profile, and check if the same issue still occurs.

I hope this information is helpful!

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".   

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.