Using classic Outlook for Windows in business environments
This was a long-time issue with the original outlook app. But there is a fix.
First, the "advisor" has an issue with understanding the product in question, as a result they continue to refer to and provide "fixes" for the original outlook, not the NEW OUTLOOK FOR WINDOWS. The NOFW, is replacing the MAIL APP that comes preloaded with windows.
The app... Regarding the current MAIL APP, you are able to CLOSE (not minimize) the app and STILL receive message notifications. It's straightforward, close the app and still get popup notifications (in windows notification panel).
With the NEW OUTLOOK FOR WINDOWS APP, it behaves differently. If you close the app, that's it, it's closed, and we receive NO NOTIFICATIONS.
Going back to the original outlook for desktop, it had the same issue. For the longest time Microsoft never addressed this issue. You were stuck having to keep the app open to receive notifications.
Now the (sort of) fix.
Microsoft finally addressed the issue and added the option to right click the icon in the taskbar (far right) and tick the option to "hide when minimized".
This is the best Microsoft's done to address the issue, unlikely we will ever be able to "close" the app and still receive notifications. This is a decade long issue, don't hold your breath on a fix. In the meantime, you can tick on the minimize to tray option and to remember to click minimize rather than close.
I have tested this solution, and it works, At least the app is no longer in my taskbar, taking up limited space. Now it's tucked away in the tray.