According to the Pennsylvania Secretary of state, there is no such law firm as Adam and Patterso (or Adam and Patterson if you mistyped it) doing business in the state of Pennsylvania.
If you are in another country and got an unsolicited email by a US law firm, that would be very suspicious. That is not how law firms conduct official business. Emails are not legally sufficient documents. Any bona fide legal notice would come to you via registered or certified mail.
Is this company claiming you have won an international contest? If so, it's a scam. There is NO SUCH THING AS AN INTERNATIONAL SWEEPSTAKES OR LOTTERY. Scammers would have us believe otherwise, but they are lying. The many conflicting laws among nations make international contests a legal impossibillty.
If you received an email that you are the beneficiary of some inheritance from a long lost relative, that scam has been around for longer than the internet, and you would NEVER hear of a real legacy via an email from an unknown law firm.
This is a way scammers phish for your personal information and then try to swindle money from you which they say you will have to wire them in order to collect your prize or legacy. Any unsolicited email giving you news which is much too good to be true is ALWAYS a scam.
If neither situation I mentioned above applies to your dealings with this so-called law firm let me know why they have contacted you. Also tell me the name of the so-called Pennsylvania lawyer and I can look him up as well and see if there is any such person.
But this looks like a scam to me and I'm confident already that's what it will prove to be.