thats a difficult one mate, coz no matter how much he betrayed you in the past, u dont wana appear ungrateful which u feel would be lowering your standards. Maybe a text or a card to him with just a small note sayin thanks for the cards/money and that he really shouldnt have. keep it friendly, short and sweet. Only problem is if u do tx him or make that contact, he may then be feeling he has won u over and thats something u maybe dont want to ever happen coz of the past

best of luck mate, but as said, its a difficult one