Complaint Review: KINGSWAY NORTH AMERICA VACATIONERS SWEEPSTAKES

I receive the same letter from Kingsway Financial Services Inc and a check in the amount of $2,946.75 USD, issued by US Bank. Letter says that I need to deposit this check in my bank account to pay for processing and non residential tax fees for them to send the balance of $17,053.75 USD. This is scam. Why is it that the envelope does not have a return address? How did these people got my address?

San jose
san jose, California
U.S.A.