Mail belongs to hunters and shamans (plus pre-40 warriors and paladins in the classic editions), making it one of the thinner armor markets.
Mail (Armor)
Auction-house prices and price history for Mail in Season of Discovery.
759 items in Armor › Mail are currently auctionable in Season of Discovery.
Prices refresh about twice a day from TradeSkillMaster (TSM), so a brand-new listing can take half a day to appear.
Mail listings link to price-history pages with per-realm buyout, average, and median data for Season of Discovery.