Dear Leah,
I have been deeply impacted by your contacting me and appreciate the spirit behind it. I do not wish to cause you hurt. On reflection though, and after seeking counsel from a trusted advisor, I believe that there would be no good purpose served by us having further contact. And also, I respectfully ask that you not contact me, nor by extension any of my family and treat this matter in confidence.
I wish you all the best in your life and I am pleased to see from what I can tell from your web presence that you are a good and successful person.
Sincerely,
(birth father - name withheld)