Impersonating a federal law enforcement official is, I think, a federal offense. I suspect you will not get the 5.7 million dollars. I could be wrong. But I think the FBI would at least like to hear about it, and if there is a real agent by this name, he would likely want to hear about this too. But what do I know.
Impersonating a Federal law enforcement officer is indeed a Federal offense. If you forward this to the FBI, include headers.
A google search reveals that a lot of 419 scammers use the globomail domain, enough to assume that anything from such domain is a scammer.
When I worked at a doctor's office, I once got a call from a guy claiming to be an FBI agent named something common like James Smith (he had an accent you could cut with a knife). He said he had speak with the Dr. I told him he was with a patient, but I could take a message. He demanded that I get the Dr. right now! I then asked him if he knew the penalty for impersonating an FBI agent... he hung up.