Fix Outlook Stuck on Synchronizing Subscribed Folders (2025 Guide)

Outlook Issues • Oct 27, 2025

Fix Outlook Stuck on “Synchronizing Folders” in Windows (Step-by-Step Guide)

Microsoft Outlook is one of the most powerful email clients, but sometimes it stops working properly, especially when users notice “Synchronizing Folders” at the bottom status bar for a long time. This issue usually happens when Outlook cannot properly connect or sync with your mail server. In this FixTechGuide tutorial, we’ll explore the causes and give you clear, step-by-step solutions to fix it fast.

Key Takeaways

  • Outlook “Synchronizing Folders” error appears when your mailbox is not syncing properly with Microsoft Exchange or IMAP servers.
  • Slow internet, corrupted OST files, or large mailboxes often cause this issue.
  • Clearing sync conflicts, disabling add-ins, and repairing the OST file usually solve the problem.
  • These steps apply to Microsoft Outlook 2016, 2019, and Microsoft 365 versions.

1. Why Outlook Gets Stuck on “Synchronizing Folders”

The “Synchronizing Folders” issue occurs when Outlook fails to update folders with new emails. The reasons include:

  • Corrupted OST file: When the local Outlook data file becomes damaged.
  • Large mailbox size: Too many emails or attachments slow the sync process.
  • Faulty add-ins: Third-party add-ins can interrupt communication with the mail server.
  • IMAP sync errors: Slow or unstable connections to the mail server.
  • Antivirus scanning emails: Email scanning tools can delay synchronization.

2. Step-by-Step Fixes

Step 1: Check Internet and Server Connection

Make sure your device is connected to a stable internet connection. Then, open Outlook and go to Send/Receive > Work Offline — if you’re offline, turn it off. Check if your Exchange or IMAP server credentials are correct.

Step 2: Empty Sync Conflicts Folder

Outlook creates a hidden folder named Sync Issues > Conflicts where failed items get stored. Open that folder and delete unnecessary items to reduce sync load.

Step 3: Disable Faulty Add-ins

Go to File > Options > Add-ins. Choose COM Add-ins and click Go. Uncheck all unnecessary add-ins and restart Outlook to see if synchronization improves.

Step 4: Repair the Outlook OST File

Locate your OST file by navigating to: C:\Users\YourUsername\AppData\Local\Microsoft\Outlook\ Then use the built-in repair tool:

  1. Close Outlook completely.
  2. Open Control Panel > Mail > Data Files.
  3. Select your account and click Open File Location.
  4. Run SCANPST.EXE (Inbox Repair Tool) and follow on-screen instructions.

Step 5: Create a New Outlook Profile

If none of the above methods work, create a new Outlook profile:

  1. Open Control Panel > Mail > Show Profiles.
  2. Click Add to create a new profile and reconfigure your email account.
  3. Restart Outlook and check if synchronization works normally.

3. Preventive Measures for Smooth Outlook Performance

  • Regularly compact and archive your mailbox to reduce file size.
  • Keep Outlook updated to the latest version.
  • Exclude Outlook data folders from antivirus scanning.
  • Schedule weekly cleanup of Sent and Deleted Items folders.

4. Advanced Fix: Reset Send/Receive Settings

In Outlook, go to File > Options > Advanced > Send/Receive. Create a new Send/Receive group and delete the old one. This resets background sync settings that might have gone corrupt.

Conclusion

When Outlook gets stuck on “Synchronizing Folders”, it’s usually a sync or file corruption issue — not a permanent failure. By following these methods step-by-step, you can restore full email synchronization without reinstalling Outlook. FixTechGuide continues to help users resolve Outlook and Office 365 errors quickly and safely.

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