Although many pots are raked, it has become standard for some of them not to be. Generally speaking, hands that end preflop are not raked at all. Additionally, the rake is taken in specified increments, like $0.05 for every $1 in the pot. In this particular case, all pots smaller than $1 would be rake-free.
Furthermore, uncalled bets are not raked. If someone makes a bet or raise and the opponent folds, ending the hand, then these final chips put into the pot are returned back to the bettor, and rake is taken only on the amount actually in the middle of the table.