A single password prompt is normal. Outlook repeatedly asking for your password, over and over, every few minutes, almost always points to one of these causes.

1. Clear Saved Credentials in Windows Credential Manager

1. Search for Credential Manager in the Windows Start menu and open it.
2. Click Windows Credentials.
3. Look for entries starting with MicrosoftOffice16_Data: or containing your email address, and remove them.
4. Restart Outlook and sign in fresh when prompted.

2. Turn Off "Always Prompt for Logon Credentials"

1. In Outlook, go to File > Account Settings > Account Settings.
2. Double-click your email account.
3. Click More Settings, then the Security tab.
4. Uncheck Always prompt for logon credentials, then click OK.

3. Check for a Clock or Add-in Problem

Modern authentication relies on your computer's date and time being accurate — if the clock has drifted, sign-in tokens can fail validation and Outlook will keep re-prompting. Confirm your system clock is correct and set to sync automatically.

Third-party antivirus or add-ins that scan email can also interfere with the sign-in process. Go to File > Options > Add-ins, click Go next to COM Add-ins, and try unchecking anything non-Microsoft to see if the prompts stop.

4. Rebuild the Outlook Profile

If the prompts continue, the Outlook profile itself may be corrupted. In Control Panel, search for Mail, click Show Profiles, create a new profile, set it as default, and re-add your account.

Common Questions

Does this mean my account has been hacked?

Usually no — this is almost always a local Outlook or Windows issue, not a sign of compromise. That said, if the prompts started right after a suspicious email or login alert you didn't recognize, change your password and enable multi-factor authentication as a precaution, then work through the steps above.

Why does this happen more with shared or delegated mailboxes?

Shared mailbox access relies on cached permissions and tokens that can go stale faster than a normal account, especially after a permissions change. Removing the shared mailbox and re-adding it often clears this up.

I fixed it once, but it came back after a few weeks. Why?

This is often the sign of a genuinely expired or misconfigured credential (e.g. a password change that didn't fully propagate) rather than a one-off glitch — if it recurs, it's worth having your IT admin check the account's authentication settings rather than repeating the same local fix each time.