No it’s not a credible threat. He used many different accounts to send the same threat directly to hundreds of students. The VA Tech Police just released a statement saying other institutions received the same emails. I was wondering which ones. Understandably some instructors cancelled classes while others held classes. The mailings were at about 1:30 pm today. It takes about two seconds to do a reverse email check and apparently someone is being questioned. From the syntax I think he is not a native speaker of English.