Remove Mail from macOS to clear up space
I want to stop using Mail (from iCloud) on my Mac. I only use it on my iPad. If I ever need it on Mac, I'll check icloud.com.
So in Preferences section Apple ID, I've deselected iCloud Mail. And in Preferences section Internet Accounts, I've deselected Mail for each and every account listed there.
But when I check Storage Management.app, I'm still seeing 5+ GB of Mail. How do I delete that?