This is an incredibly useful lesson. In today's world of email and texting students tend to blur the lines between formal and informal. Teaching students how to write a proper email to a professor (or really any professional) is an extremely valuable skill. The lesson walks through ideas on how to teach this skill.
If the instructional design incorporated more detail on exactly what students will be asked to do (example: sample assignment with rubric) it will become more accessible for educators to use. When it comes to evaluation it is stated that students will be working together to revise their emails, however, the role of the teacher is not directly addressed, this is why a rubric might come in handy.
It would be beneficial for there to be an activity incorporated with a rubric. In addition it would be more pedagogically sound if examples of good/bad emails were provided for students to dissect (this could be adapted to be done in class with just discussion or done using some sort of on-line discussion forum). This lesson could easily be transformed into a Webquest format with more detail on instructional procedure and more direction provided for students. It says that it will be given in Moodle but it is not clear on what that will look like (provide a link if it is already created in Moodle).
The technology component can easily be adapted to any email service that students are using. Perhaps it would be a good idea to incorporate an overview lesson of how to use different features of the email service before beginning the email writing piece.
There is a colaborative component where students will be commenting on each other's emails (this could be adapted to be done in class with just discussion or done using some sort of on-line discussion forum). Either way it does a great job of opening the door to pair-sharing which is a fantastic pedagogical strategy.