I searched for any information on the Saint Matthews Churces (a.k.a Prayer By Mail). The first result page was loaded with scam reports, alerts, accusations, investigation results, and the like. The "church" itself stated its case. It's only fair that I quote their position. After all, I did make fun of them yesterday.
Saint Matthew’s Churches receives tithes and offerings based on the Scriptures, and uses church donations to buy postage and printing of gospel sermons, books, magazines, and other literature that we give away free of charge. Saint Matthew's Churches does not sell anything. In its mail sermons, it preaches that God answers prayer, which cannot be construed as a mail scam or mail fraud.
However, the published sermons and sacred literature sent free of charge by Saint Matthew’s Churches crosses the paths of atheists; communists; drug dealers; criminals; the lunatic fringes of society; those who hate the United States, God and Christianity and those who hate us because we are gospel missionaries. They accuse all churches which mail sermons of mail scams and mail fraud.
There it is.