/

Try adding him on steam or something, if he ignores every kind of approach you do to him then you should create a support ticket with proof of that you sent it to him (atleast that is what i would have done).

This is why sending gifts/keys via email is never a good idea.

But he has to accept it RIGHT NOW, before he goes to sleep.

They can't mark it as "not received" until seven days have passed.

You cannot mark it as not received until after 7 days. This is not the case.