Are you sending from your school domain? Often systems block mass mailings as a SPAM protection and limit the number of mailings going out. (Spam detection systems will block mail that originates outside yet suggests that it is From the inside domain) Try sending from an external mail account. In fact you could use your gmail account. Using an external mail account has solved this problem for me.
This is a quick guess about your problem. I don't think this is a Flashlight issue but an issue of related to how your network is setup to manage SPAM.
Frank Parker