Did you miss the part where you are given an option?! Like cease and desist or I'll . . .
Or do you intend to press on with your attack upon the individual's reputation and that of his business inviting a lawsuit and the expense of defending one? Yes expense! Because not having a clue about court rules, civil procedure, the rules of evidence, jury instructions, trial technique, etc., etc., you'd be lost at sea without experienced trial counsel.
Just because you'd be entitled to defend pro se doesn't mean you'd know how!
While I agree that most people are ill-equipped to handle a defamation lawsuit on their own and have no clue at how costly these lawsuits can be, there has been no lawsuit filed yet, latigo. In fact, from the little that has been written, it appears there is a good chance there will be no lawsuit and that the person who sent the email does not have any lawyer (free or otherwise).
Although it could be smart for jolly808 to have his review and the email he received looked at by a professional, this to see if the review is defamatory and the removal of the review warranted, the email received by jolly808 could just be a poorly-written attempt by the person/entity reviewed to silence a legitimate critic through intimidation.
Then again, it could also be the first step required under the law before filing a defamation lawsuit. Whether it is or not would depend on the state.
Perhaps jolly808 will return to provide his state name and more information about the review he wrote.