This guys real email address is: "SMerriman AT perkinscoie DOT com" so if the mail you have is sent from that address then i would suggest its real, however anyone could knock this email up in an hour so try not to panic just yet, check the address of the mail as i said above, and call them if the mail is correct to confirm.
If it is correct just take down your service if you are worried, no need to send them everything that they have asked for, they hold no legal right to that info.