Outlook becomes unresponsive after 10 - 15 minutes

Follow these steps in order, testing Outlook after each major step:

1. Install latest Windows and Office updates

• Make sure Windows and Microsoft 365/Office are fully updated, as many Outlook freeze issues are fixed in updates.
• Use the guidance in Install Office updates from this article: Classic Outlook not responding, stuck at "Processing," stopped working, or freezes.

2. Start Outlook in Safe Mode and check behavior

• Close Outlook.
• Start in safe mode:
  • Windows 10/11: Start menu → type Outlook.exe /safe → Enter.
• Leave it open 15–20 minutes and check if it still stops updating or becomes unresponsive.
  • If it works in Safe Mode, an add-in or integration is likely causing the freeze.

3. Check for long-running operations or dialog boxes

• When Outlook appears frozen, check the status bar at the bottom:
  • If it is processing a large number of items (deleting/moving/syncing), allow time to finish.
• Press Alt+Tab to see if a hidden dialog box is blocking Outlook (for example, a confirmation prompt). Close or respond to any dialog.

4. Repair Office

• Close all Office apps.
• Control Panel → Programs and Features.
• Right-click Microsoft 365/Office → Change → run a repair as described in Step 4 of this article: Classic Outlook not responding, stuck at "Processing," stopped working, or freezes.

5. Repair Outlook data files

• If the data file is damaged, Outlook can hang and stop syncing.
• Use the Inbox Repair Tool (SCANSPST.EXE) as described in Step 5 of the same article by following Repair Outlook Data Files (.pst and .ost).

6. Check antivirus integration with Outlook

• If antivirus software integrates with Outlook or installs add-ins, it can cause freezes and “not responding” states.
• Disable Outlook-specific integration or Outlook add-ins from the antivirus product (do not disable real-time protection entirely) as described here: Outlook not responding error or Outlook freezes when you open a file or send mail.
• If needed, contact the antivirus vendor for exact steps to exclude Outlook integration.

7. Create a new Outlook profile

• A corrupted mail profile can cause Outlook to hang after running for a while.
• In Control Panel → User Accounts → Mail → Show Profiles:
  • Remove the existing profile.
  • Select Add, create a new profile, and reconfigure the email account as described in Step 10 of Outlook not responding error or Outlook freezes when you open a file or send mail.
• Start Outlook with the new profile and test for 15–20 minutes.

8. Run the Classic Outlook Advanced Diagnostics troubleshooter (if using classic Outlook on Windows 10 or later)

• This tool automatically checks many of the common causes (add-ins, profile, data files, etc.).
• Use the Classic Outlook Advanced Diagnostics troubleshooter from Outlook not responding error or Outlook freezes when you open a file or send mail and follow the instructions in the Get Help app.

9. Consider POP/Windows update issues (if using POP accounts)

• If any accounts are POP and the issue started after a recent Windows 11 update, there is a known bug where classic Outlook POP profiles hang and freeze.
• The moderator guidance in Outlook Freezing and Not Responding and Not saving changes when ending the task - Microsoft Q&A indicates the temporary fix is to uninstall the specific Windows update (KB5074109) via Windows Update → Update history → Uninstall updates, if that update is present.

If, after these steps, Outlook still freezes in both new and classic experiences, collect details (Windows version, Outlook build, account types such as POP/IMAP/Exchange, antivirus product, and recent Windows updates installed) and provide them when contacting Microsoft Support or posting in Outlook Tech Community for deeper investigation.

References:

• Classic Outlook not responding, stuck at "Processing," stopped working, or freezes
• Outlook not responding error or Outlook freezes when you open a file or send mail
• Outlook Freezing and Not Responding and Not saving changes when ending the task - Microsoft Q&A