One thing I hate about the Mail app on my Mac is how when I go to enter someone's name to email them, macOS has a nasty habit of picking the wrong email address for that person and I always notice it when it's too late.
I had this happen to me the other day and my email was sent to the wrong inbox of that person – an email address that they don't even use anymore – so they never got the email I sent and I had to resend it.
If you've ever had this happen to you before, then you're reading the right tutorial, because we'll be showing you how to delete email addresses from Mac Mail history so they aren't auto-suggested for you when you start to type someone's name.