I did something similar once and accidentally got a coworker fired because of it... I had to send a write up of an incident where one of my cashiers yelled at a little kid in our store to the HR manager, because the kid's parents were rightfully very upset. I was not familiar with the email address book on our computers, there were multiple categories with the same addresses so I just sent it off to "Human Resources"... I come back from my day off to find that I sent that email to the ENTIRE HR department, and when so many people saw this incident, there was a lot of pressure on the store manager to fire her immediately. Though it was on accident, everyone working there was sort of relieved - she was rude, racist, and generally a pain in the ass anyway.