How to reset Microsoft Outlook on MacOS and resync to IMAP server

Before proceeding with the reset steps below, you may optionally try one quick validation:

Alternative (Optional Check):

You can install the free Mozilla Thunderbird email client on your Mac and configure your email account there.

• • If Thunderbird synchronizes all emails correctly and does not restart downloads, this confirms that the mail server is functioning perfectly and that the issue is limited to Outlook on the Mac.

  • You may then proceed with the Outlook reset steps below with confidence.

If you choose to proceed with resetting Outlook, please follow these steps carefully and in order. This process removes corrupted local data and forces Outlook to rebuild your mailbox cleanly.

1. Safely close Outlook and back up your data

1. 1. Open Outlook.

   2. From the top menu, click Outlook → Quit Outlook.

   3. Wait 10–15 seconds to ensure it is fully closed.

   4. Open Finder.

   5. Click Go in the top menu and select Go to Folder…

   6. Paste this path and press Enter;
      
      

      ~/Library/Group Containers/UBF8T346G9.Office/Outlook/

       

   7. You will see a folder named Outlook 15 Profiles (or similar).

   8. Copy this entire folder to your Desktop.
      This is your safety backup.

2. Remove the existing Outlook profile

1. 1. Open Applications → Microsoft Outlook.

   2. From the top menu, click Outlook → Settings.

   3. Click Accounts.

   4. Select your email account.

   5. Click the – (minus) button to remove it.

   6. Close Outlook again.

3. Clear Outlook’s local cache and identity files

1. 1. Open Finder.

   2. Click Go → Go to Folder…

   3. Paste this and press Enter:
      
      

      ~/Library/Group Containers/UBF8T346G9.Office/

       

   4. Locate and delete the folder named Outlook.

   5. Empty the Trash.

(This only removes local copies on the Mac. Your emails remain safe on the server.)

4. Recreate the email account in Outlook

1. 1. Open Outlook again.

   2. It will ask you to add an account.

   3. Enter your email address and password.

   4. Follow the on-screen steps until setup completes.

   5. Let Outlook begin downloading your mailbox.

5. Allow a clean, uninterrupted sync

1. 1. Keep Outlook open.

   2. Ensure your Mac remains powered on and connected to the internet.

   3. Do not close Outlook or put the Mac to sleep during this process.

   4. The first sync may take time, depending on mailbox size.

   5. Once completed, Outlook should behave normally without restarting downloads.