Using Classic Outlook on Windows for personal email, calendar, and contact management
Sorry to hear that you’re having trouble with this situation. Could you please share a little more information? Are these Microsoft accounts such as Outlook.com/Hotmail, or third-party email accounts that you are trying to use in Classic Outlook?
For each affected account, are you able to sign in successfully through the email provider’s website using a web browser with the same password? Also, regarding the outgoing server password error, could you please share the exact error message or a screenshot of it, making sure no personal or sensitive information is visible?
Finally, is the issue occurring on the same Windows computer for both accounts, or are you referring to two different devices?