1. Can you log in to mail.letu.edu?  If yes, restart Outlook.
    
2. Use your UserName@letu.edu email address when prompted for credentials and check the "remember credentials" box.
   If prompted again, click Cancel. 
   If prompted again after Cancel, move on to step 3.
    
3. 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.

Mac Outlook -- Choose Tools | Accounts | type your LETU password in the password field.  Close the Accounts window.  

4. Clear your cached passwords (Note: you may need Admin rights to do this) - Windows

• Exit Outlook and Teams.
• Choose Start | Control Panel | View by Large Icons (upper right of window) | User Accounts | Manage your credentials (left column)
• Select all credentials for Microsoft, Outlook, OneDrive, and Teams and choose Remove from Vault
• Exit and reboot your computer.

Clear your cached password - Mac

• Exit Outlook and Teams
• Select Finder | Utilities | Keychain Access
• In the search field, type Exchange.   Delete all entries for your Exchange account.
• In the search field, type adal.   Delete all entries who type is MicrosoftOffice.....
• In the search field, type office.   Delete all entries named Microsoft Office Identities Cache 2 and Microsoft Office Identities Settings 2
• Quit Keychain Access.
• Restart Outlook.  You will be prompted to authenticate. 
   

5. Rename the Outlook .ost file (if get error about "cannot open set of folders")

• Exit Outlook and Teams.
• From the Start menu, choose Run.
• In the Run window, type this path in the Open box  "%LOCALAPPDATA%\Microsoft\Outlook\"
• Click OK
• Find the .ost file and rename it (you may need to Show Hidden Files and Show Extensions to see the file)
• Restart the computer
• Restart Outlook

6. Creating a New Profile (when you create a new profile, you will need to re-add any email account you check including shared departmental accounts)

• Exit Outlook and Lync
• Choose Start | Control Panel | View by  Large Icons (upper right of window) | Mail (may say Mail 32-bit)
• 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. 

NOTE:  you will need to reopen any .pst or archive files you have.