Using classic Outlook for Windows in business environments
If you subscribe to Microsoft 365 (used to be Office), I think that you should still have access to (old) Outlook. The free email client before New Outlook was Mail. Perhaps that's what you're thinking of? There's also an app named Outlook on the Webb, which used to called Outlook Web App or Outlook Web Access. And none of these should be confused with outlook.com, although Microsoft tries their best to confuse us with their naming. I have no idea why they keep changing the names. Very weird.