Have you been wreaking havoc with the Seed of Destruction glitch on the PTR? Skinning Taurens for leather? Or maybe just abusing the Arena rating system? Whatever the reason, not everyone got a Winter Veil recipe in their mailbox yesterday.
Everyone should have received something in the mail based on their tradeskill professions. But not everyone did. And since those who do get them can't give them away (they're BoP), it has created a market for those who can make them and cries of foul play for those who didn't get anything.
At first, Blizzard directed players to petition in-game, but then they realized the problem was more widespread. Now they are looking into the script that determines who receives what recipe in their mailbox. They aren't giving out any details right now, but ask players to hold off on petitioning until they can figure out the root of the problem.
Until Blizzard determines the problem and implements a solution, you'll have to hit the Auction house, Guild bank or qq in the Trade channel if you want Red Winter Clothes or Hot Apple Cider.
[Thanks Keeler for the tip!]