Dear Judy,
I’m writing the letter for the purpose of conveying my thanks for your warm reception [during my recent visit to your country].
Your friendly warmth made it possible that I have a pleasant time in America. And it was your generous help that allowed me the chance to know the American culture better. In addition, I consider in an honor for me to make a friends of you. I hope that you would visit our country in due course so that I could enjoy the opportunity to repay your kindness and refresh our friendship. Please accept my sincere thanks. Wish you all the best.
Yours truly,