If the US.ARMY.MIL address is really him it is easy to blast him back. Merely send a letter of complaint to firstname.lastname@example.org
You also should cc that letter (e-mail) to the address of the provost marshall of the us.army.mil and to the general in charge of the US Army. US Army website
should get you close enough to the right address to stop/investigate this problem.
You see, if this Trevor.L.Corad's e-mail address is being used by someone else, that is a federal crime. That machine is a US. Government machine and forging e-mail using an address from there is a very bad thing. Jail time would ensue. If it is indeed him doing it; shit will rain down on him from very high. That's another reason why you want to cc the General in charge of the Army. He will check and have Shit Rain fall on anyone who doesn't get it stopped quickly. What this person is doing is now a crime in the US. We just passed some new laws.
Believe me when I tell you that the Army makes a big thing about protecting women and children. The only good thing most of these Army guys have is "The Girlfriend Back Home" and they regularly die for them. They are the last people to put up with a scuzball harassing a woman.
OK. I looked around over there and there is a quick thing you can do that is guaranteed to cause an investigation. Go to file a FOIA request
Somewhere there they will ask you "why?" Tell them the story. Tell them you are trying to find out who this scuzball is so you can have him prosecuted. (They cannot refuse the FOIA.) What this will do is cause them to verify whether this guy did it. If he did, he'll probably get at least 30 days in the brig. He should never contact you again.
This is the guy... Sergeant Major of the Army
He will personally deball the guy. I'll look a little more and see if I can find a direct e-mail address.