User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:28.0) Gecko/20100101 Firefox/28.0 (Beta/Release) Build ID: 20140314220517 Steps to reproduce: I accidentally sent an email with 576 recipients in the To: field when I had meant to use Bcc: Actual results: All 576 email addresses were exposed in all the emails. Expected results: It would have been better if I had received a warning (allowing to cancel my email) that my list of To: recipients had exceeded either a set number (10?) or a number that I could set for myself.