Dear ,
Thank you very much for/Thanks a lot for/Many thanks for /I’m writing to you about my gratitude for /I’m very grateful to you for .(开门见山地交代感谢原因)
I hope to have the opportunity to express my gratitude to youepay your kindness. I will feel very honored and pleased if .(提出回报对方的方式)Would you please let me know ?(希望对方给予回应)Thank you again for what you have done.(再次表达感谢)
Yours sincerely,