Don't listen to what most of these people are saying on here. Ask a lawyer.
People have been charged Federally under this: 18 USC 1461 - Mailing obscene or crime-inciting matter.
It doesn't matter if you use the U.S. postal service, UPS, FedEx, DHL or on the back of a fucking donkey. As soon as you ship something across state lines it's a Federal offense, no matter what service you use.
I always scratch my head at why people think if you're using the U.S. postal service its a federal offense, but if you use a private company like FedEx, it's not
