Supplicants send their mail to the unseen powers that be

http://www.egypttoday.com/article.aspx?ArticleID=4482
"Archaeological documents show that from as early as the Old Kingdom up to modern times, an endemic and persistent distrust in medicine and justice, as practiced in the land, often led the Egyptians to address their requests for health and legal redress directly to their dead relatives and the gods." A discussion of letters to the dead, from the Old Kingdom onwards.