Can you put church flyers on a Mailbox?

In the United States...you can't put anything in or on a mailbox. Think of it like US. Government Property. They will come after you whether you are a church, or Boy Scouts. "no part of a mail receptacle may be used to deliver any matter not bearing postage, including items or matter placed upon, supported by, attached to, hung from, or inserted into a mail receptacle." http://pe.usps.gov/archive/html/dmmarchive0810/d041.htm