If you are being prompted for your password in Outlook try the steps below, one at a time to resolve the issue.
- Can the user log into Webmail? If yes, have them restart Outlook.
- Clear your cached passwords (Note: you may need Admin rights to do this)
- Exit Outlook.
- Choose Start > Settings > Accounts > Email & app accounts
- Select the Outlook account then click Manage > Delete account
- Exit and reboot your computer.
- Rename the Outlook .ost file (if get error about "cannot open set of folders")
- Close Outlook.
- Start Run by pressing Windows Key + R.
- In the Run window, copy and paste this path in the Open box "%LOCALAPPDATA%\Microsoft\Outlook\"
- Click OK
- Find the .ost file related to your account and rename it
(you may need to Show Hidden Files and Show Extensions to see the file) - Restart the computer
- Restart Outlook
- Verify that prompt for Credentials isn’t checked in profile:
- Start Outlook
- Choose File | Account Settings | Account Settings
- Select your Exchange account
- If prompted, in the Password: text box, type your password
- Click the Change button
- Click the More Settings button
- Select the Security tab
- Deselect the "Always prompt for logon credentials" check box
- Click OK,
- OK
- Choose Close
- Restart Outlook.
- Creating a New Profile
- Exit Outlook
- Start Run by pressing Windows Key + R.
- In the Run window, type "Control Panel"
- Click OK
- In the Control Panel double click Mail [may say Mail 32-bit or Mail (Microsoft Outlook 2016)]
- Click Show Profiles
- Click Add
- Type the name of the profile e.g. your name and click OK
- Enter your name and email if it doesn’t default in automatically
- Click Next – it should auto configure
- Click Finish
- Back in the Mail window – Select your new profile in the "Always use this profile" dialog box and click Ok.
- Open Outlook and then re-open any .pst or archive files you have.