"I want to take this opportunity to thank you for your past support. I'm not sure if you are aware, but your last donation was in May 2009 for $20. There is a reason I am sharing this with you.
I admit that I felt a tinge of guilt when I read that opening. Whether I make a gift or not, the fact that the mailing made me feel something is a good thing. These are hard times. Non-profits must go to greater lengths to try to secure gifts, even if it means alerting me to my lapsed giving history, citing month, year and amount.