Solutions:
1. Switch to using webmail, accessing your account via your email provider's website ; OR
2. Use the Mail app that comes pre-installed with Windows (NB: NOT recommended!) ; OR
3. Use a third-party email app, such as the mighty Thunderbird:
https://www.thunderbird.net/en-GB/
If you've no longer got Outlook 365 working on your PC, you might well have lost your office apps (such as Word and Excel) as well. If so, simply replace them with LibreOffice:
https://www.libreoffice.org/discover/libreoffice/