All Users: send email to all users in the course
All Group: send email to all group users
All Students/TA/Professors: send email to users with a specific role
Select Users: Select specific users
Select Groups: Select specific groups
※ If students use 'send email' function, they can only select TA/Instructor as the recipient
When selecting [All users]
1) Write subject and message
When selecting [All Group]
1) Write subject and message
4. Send Email-Select User
1) Click the recipient of the email
2) Select/Delete by clicking the arrow icon