Couple of hints that may help:
1) Look carefully at the sender. Indeed it will read the Coach's name, but it may not be coming from the Coach's email client. Rather, it may be coming from a 3rd party email service provider (ESP). The Coach loads up a list into the ESP (first name, last name, HS name, email address, etc.), creates an email template, and sends the email so that it looks to be personalized.
2) If the Coach is using an ESP, he can track who has opened the email and who has clicked on any of the emails. Be aware.
So if you see that the email came directly from the Coach's email client, then you know it was completely personalized. However, if the email came under the Coach's name but via a 3rd party provider, most likely it was a part of a broader mailing.