Hi again -
It sounds like you were receiving Notifications from both Edge browser for your Mail website, and from Mail app, which would explain why there are two.
To adjust Edge browser website notifications see here:
https://support.microsoft.com/en-us/microsoft-e...
https://www.lifewire.com/manage-notifications-i...
Feel free to ask back any questions. Based on the results you post back I may have other suggestions if necessary.
______________________________________________
Standard Disclaimer: There are links to non-Microsoft websites. The pages appear to be providing accurate, safe information. Watch out for ads on the sites that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the sites before you decide to download and install it.