Thank you very much ( very, very much) (ever so much) (most sincerely) (indeed) (from the bottom of my heart).
很（非常）（非常非常）（最真誠地）（確實）（衷心）感謝您。
Many thanks for your kind and warm letter.
感謝您友好而熱情的來信。
Thanks a million (ever so much).
萬分（非常）感謝。
Please accept ( I wish to express )my sincere (grateful) (profound) appreciation for ...
請接受（致以）真摯的（衷心的）（深切的）感謝……
I sincerely (deeply) (warmly) appreciate ...
我真摯的（深深的）（熱情的）感謝……
I am very sincerely (most) (truly) grateful to you for ...
為了……，我非常真摯的（深深的）（真誠的）感謝您。
There is nothing more important (satisfying) (gratifying) to me than to receive one of your letters.
再也沒有比收到您的來信更使我覺得重要（快慰）（感激）了。
Your letters are so much fun (comfort) (entertainment) (company).
您的來信充滿了樂趣（給了很大安慰）（帶來了歡樂）（使我不感寂寞）。
Your most courteous (considerate)(delightful)letter...
您那彬彬有禮（體貼入微）（令人欣慰）的來信……
I cannot tell you how much your letter delighted(relieved)(amused)(enchanted)me.
我無法告訴您，您的來信使我多么高興（寬慰）（覺得有趣）（陶醉）。
I love the way you say (put) things in your letters. You make even the smallest incident seem so interesting(important)(charming)(mysterious).
我很欣賞您在信中描述各種事物的手法。您的妙筆使細小的事情都顯得很有趣（重要）（動人）（神秘）。
It was good (fine)(charming)(thoughtful)of you...
承蒙好意（美意）（盛情）（關心）……
It was nice(characteristically thoughtful) (more than kind) of you...
承蒙好意（特別關心）（十二分好意）……
At the outset, I want to thank you for your kindness to me and for your compliments.
首先，我要感謝您對我的'友愛和問候。
Believe me, I am truly grateful for...
我確實真誠地感謝你……
We were deeply touched by ...
……使我們深受感動。
It is a hopeless(definite)(positive)understatement to say that I am deeply (sincerely)(truly)grateful.
這就是說“我深深的（真摯的）（真誠的）感謝”遠不足以（不能確切）（不能明確）表達我的謝意。
It‘s generous of you to take so much interest in my work( to give me so much of your time) (to show me so much consideration).
承蒙對我的工作如此操心（為我花費這么多時間）（對我如此關懷）。
We are indebted to you...
我們感謝你……
I regret very much that I did not have an opportunity to thank you personally for ...
未能面謝，深表遺憾。