This reads like a schizo post internet tough guy meme. I almost guarantee this isn't a real intel email. Literally "I'm a marine with x confirmed kills do you know who you are fucking with." energy. It rambles about way too much stuff to try to establish legitimacy where a real email from an Intel agency would be clear concise, minimal/no typos and would provide a tiny piece of evidence to show they are serious without showing the whole hand. This isn't that.