Yeah, two emails. first the mail with the song, named "mewithoutYou product download", then "mewithoutYou invoice (number)". Got the both of them seconds after the order went through. So strange that so many of you have problems with it?
But i got the option to download it in the store aswell, on the same page as the order receipt.
It was a link like this, "download "fox_s_dream_of_the_log_flume_MP3_D A.zip"