Hello @Gerald_Snyder, here is another feedback request thread about the inbox that might be interesting.
Inbox filter per project
Also you might wanna update the title of your feedback request a bit further so it is even more precise and easier to find for others.
By rules do you refer to being able to set up inbox rules to filter incoming messages based on various conditions and then move to a specific subfolder?
Basically you wish for the current inbox feature to be expanded to kind of replace an email inbox?