Automatically delete emails after successful import/archive

I can’t seem to figure out how to enable the deletion of emails automatically after they were imported (so I don’t have to manually go through dozens of MacOS Mail folders).

How can this be accomplished?

It can’t unless you created or modified an AppleScript to do this. There are built in Mail ApplesScripts you could look at. Do note: We would generally not write a script that automatically deletes items form peoples’ machines.