You have one week to wait.

Well here I am!! oh wait I'm not the winner... :/ well did you friend invite the person in question?

Go to his profile page: http://steamcommunity.com/id/username-here and browse his games.

Did you try to had him as a steam friend ? I had the same problem, the person did not see my mail because it was in spam folder. I made a friend request and talked to him, problem solved. Yours may be different, but if you cannot reach him with mail, try Steam...

Yep, I know about the week wait.

Didn't try to add to steam friends as it has been 26 days since he was last logged in, but will add.

Did check his games, not listed.

Will add as steam friend now, you have a good point m0l0

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAPANIC

I had such an incident where the winner did not respond or claim his key after 3 days. I just sent him another email and within half a day he redeemed it.