I got a warning email and am freaking out. How common is this?

Whattodo122
Tue, 17 Feb 2015 02:43:16 +0000

Fellow admitted student here.
What was the exact wording of the letter? Was it just “checking in?” Or was it more like “you are in danger of recension”? What are your grades normally like?
Generally these letters are sent to elicit this reaction. I have friends who were sent letters and are now freaking out and pledging to get better grades. Usually, however, their grades have dropped to at highest a C+ average, so I will admit this is a bit puzzling…