Outlook doesn't work for 4th IMAP email addy

You can download and install Outlook from different websites, and I guess you can also uninstall it in Apps in Windows as well.

https://microsoft-outlook.en.softonic.com/

You click on > Start>Microsoft Store then down to the left > Update and wait until all the Apps are updated and check again to be sure that nothing is missing.

Use Manual Setup: In Outlook, do not use the automatic email login. Navigate to File > Info > Add Account and choose Advanced options > Let me set up my account manually (or select Manual setup or additional server types)

Select IMAP: Check the box for IMAP.

Server Details: Enter the Incoming mail server (IMAP) and Outgoing mail server (SMTP) exactly as provided by your specific email host

Secure Ports & Authentication: Set Incoming (IMAP) port to 993 with SSL/TLS encryption. Set Outgoing (SMTP) port to 587 with STARTTLS or TLS encryption. Check "My outgoing server (SMTP) requires authentication"

App Passwords: If you have two-factor authentication (2FA) enabled, you will need to generate a specific "App Password" on your email provider's security page (e.g., Google or Microsoft) and use it instead of your standard password

https://support.microsoft.com/en-US/Outlook/settings-for-imap4-access-to-microsoft-personal-email-accounts

You can also Check >Control Panel>Programs>Turn Windows features on or off, if there is anything related.