It is polite and friendly and comes no less than two days after the last one.
The one who dumped (her) is casual and upbeat, which comes off as distant: "My week was busier than usual and I've enrolled in a new course. It's not something I need to know now but if I ever want to teach I'll be glad I did. How was your day off?"
The one dumped (me) tries to avoid a bitter and sad phrase yet fails: "That's good that you're taking that class. More education never hurts and usually helps! Didn't do much on my day off. Just puttered around, took a nap."