Office 2024 Outlook is denying access to email.

Test Outlook on the web from another device or network first, because the visible ERR_TIMED_OUT must be resolved before Outlook can complete its browser-based sign-in.

1. Isolate the connection problem

1. Close classic Outlook.
2. On the same PC, open an InPrivate window in Edge and access Outlook on the web.
3. Repeat the test using:
   • Another device on the same network.
   • The affected PC through a different connection, such as a mobile hotspot.

Interpret the result:

• Works through the hotspot but not the normal network: The normal network path is blocking or failing to reach Outlook. Temporarily disable any VPN or manually configured proxy, and check firewall, antivirus web protection, DNS filtering, or router security. On a managed network, ask the administrator to inspect those controls.
• Fails on every device and network: This is more likely an account or service-side problem. For a work/school mailbox, the Microsoft 365 administrator should check Service health → Exchange Online; Microsoft specifically recommends checking service health when connectivity affects users beyond one Outlook installation.^1^
• Works in the browser on the same PC and network: The connection is available, so continue with Outlook authentication and profile repair below.

Since all accounts fail together, do not change each account’s password or server settings until this network test is complete.

2. If web access works, run the authentication check

On the affected Windows PC:

1. Open Start → Get Help.
2. Search for Outlook password problem.
3. Run the Classic Outlook authentication check troubleshooter and apply its recommended corrections.
4. Then run the Classic Outlook connectivity troubleshooter if Outlook still disconnects.

These troubleshooters apply to classic Outlook on Windows 10 or later and must be run on the affected PC; they do not apply to new Outlook.^2^

3. Repair the Outlook profile only if authentication passes

1. Open classic Outlook.
2. Select File → Account Settings → Account Settings.
3. On the Email tab, select an affected account.
4. Select Repair, complete the wizard, and restart Outlook.^3^

If several accounts are present, repair one account first and verify that it remains connected before changing the others.

4. Check the account configuration if prompts continue

For accounts that previously worked, Microsoft identifies a changed or expired provider password as a possible reason classic Outlook repeatedly requests credentials. The username must be the complete email address.^4^

If an Outlook.com account was configured manually as POP or IMAP and displays a plain username/password prompt rather than the Microsoft sign-in window, remove that manually configured account and add it again using Outlook’s automatic account setup. Outlook.com connections using Basic authentication can produce recurring password prompts; OAuth/modern authentication is the supported alternative.^5^

Avoid registry changes intended for older Outlook or Windows releases; the documented Outlook 2010/2013 proxy workaround does not apply to Outlook 2024.

References

1. Fix Outlook connection problems in Microsoft 365 - Exchange
2. Classic Outlook troubleshooters | Microsoft Support
3. Fix your Outlook email connection by repairing your profile
4. Troubleshoot Outlook email setup | Microsoft Support
5. Outlook and other apps are unable to connect to Outlook.com when using Basic authentication | Microsoft Support