Data publishing center a scam?

i been getting a lot of mail saying i won money but they are asking for $20 fee for prossing and there is no way to contact them they use a po box in las vages i reported it to the postal inspectors about them sombody is renting a po box in that state in that zipcode useing many namesthey ask for cash or cheak or money order and no one sends cash throu the mail but these perple are very money hungry they dont want to work soon or later it will catch up with then one guy called me and said that i won $350 000 00but i had to pay $1200 00 to him to get the money i told him to take it out of the winnings he hung up the phone on me