Is this considered hacking?

I sat down at one of the computers at the school computer lab. Opened was an email of a clmate who called mean inbred mongoloid and she said she was going to kill me. It was a private email so I was a little scared but went back to my dorm to think about it. When I went back to my dorm, this same email was slipped under my door and that really freaked me out. I was going to show it to my professors the next day, but it seems like they already knew about it because they were extra nice to me and asked me what was wrong. I told a clmate about it and they said to keep quiet about this email because if I show it, it may look like I hacked into the email account or something like that. So I kept quiet, but it seems like the professors had security following me around that day, they tried to strike a conversation up about it showing me a video of a girl who was bullied at school. I don't know what I should do. Leave it alone? Or report it because ever since that e-mail people have been nasty to me, however my cl is a nasty cl so its hard to say what was the cause of all this.