I just read a similar email in my Spam--Have received many emails also phone calls. You should report them to the Federal Trade Commission--which I have and if you can block the number--I have this feature on my phone plan. Also place an alert with the Credit Bureaus to be safe since they have the SSN--I placed an alert on my file. They are scammers and I wish there was way they can be stopped from getting US phone numbers when in all likelihood they are in some other country. It really is annoying as they just want money to get money without working my sending threating emails and making unwarranted phone calls. Glad you posted the entire letter for others to see.
They have no idea who is getting this. I did forward this to the US Attorney of the Southern District of NY. Stupid people, they sent this to an Attorney. Debt first is a civil action and they express this as a criminal offense. To top it off, they express the use of federal agencies which is highly illegal. Lastly you cannot file a complaint via email. They have broken many statues of law. Did you notice the grammar and the lack material fact, name, address and even your proper email. Don't respond, no need to give any info.
Reply saying they are violating FDCPA - Fair Dept Collection Practices Act and that you need their information for legal purposes, bet they hang up. I told them when they called once it is VERY ILLEGAL in the US.. to threaten any law enforcement activiity and you cannot intend you will take action if you note. If I do get to court.. I kept all VM and calls to show the judge and then they will be in violotaion and probably will end up having to pay more out to you than the debt they accrued.