Using external email providers is super helpful for instructors selling courses on BMF.io. They make it way easier to send out course updates, promos, and reminders without stressing about emails ending up in spam. Plus, these tools can automate messages and even help track who's opening and clicking stuff. That means instructors can spend less time dealing with tech headaches and more time making awesome courses. It's basically a chill way to stay connected with students and boost sales without extra hassle.