I think it's very useful for e-mail writing, not only just use for work, but also in general, the teacher will give you ideas and some practice how to organize the mail structure, and the common grammar mistake in order to improve mail writing in English.
2019年09月．商用英語 ─ 如何撰寫電子郵件
Eileen is a great teacher with patience and energy. She cares about each student’s need and prepares lots of material. My favorite teacher in MTD!
2019年07月．商用英語 ─ 如何撰寫電子郵件
Elene is an experienced teacher. She provided some exercises in writing e-mail during the class and after the class. I've gained more skills in writing. I hope to take more of her classes in the future :) Thank you Elene :)