outlook is not working

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Hi Hr-Admin

You may first want to check whether you are able to sign in to your mailbox using Outlook Web outlook.cloud.microsoft or the Outlook Mobile app.

1> If you can access your mailbox via Outlook Web or Mobile, then the issue is likely related to your local Classic Outlook desktop client.

In this case, if you have administrator permissions on your machine, please try clearing the saved Windows Credentials associated with Outlook. You can close Outlook completely > Open Control Panel > Credential Manager. Remove entries related to your account. Then, open Outlook and sign in again.

Otherwise, you may need to contact your IT administrator and ask them to assist with clearing the cached credentials for your account.

If the issue persists, try:

• rebuilding your .ost file: Close Outlook > Press Windows + R > Type in %LOCALAPPDATA%\Microsoft\Outlook\ > Look for your email address and delete it. Restart Outlook.
• Create an Outlook profile - Microsoft Support

2> If you are unable to sign in across all platforms (Web, Mobile, Desktop), then the issue may be account‑ or backend‑related. In this scenario, I recommend contacting your IT administrator so they can proceed with further backend troubleshooting from the Microsoft 365 admin center or Exchange environment, as this is a user‑to‑user support forum, moderators do not have access to Microsoft internal systems or tenant‑level configurations.

Please feel free to share the results, and I’ll be glad to assist you further.

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