You guessed it, by email. Upon reading your cases, either I or my grader will email you your points and any comments we might have. In general what we will send back to you is your completed case with comments written at appropriate places. You will be able to tell our comments because they will be in all caps. Grades and overall comments are given at the end of the returned case.
The grading procedure is to place you and your partner's cases side by side on my screen and work back and forth. Thus, it is extremely important that the subject of your email/case contain the case number, your name, and your partner's name.