Many thanks for
Thank you for
Thank you very much (ever so much) (most sincerely) (indeed) (from the bottom of my heart).
很（非常）（最真诚地）（确实）（衷心）感谢您.Thanks a million (ever so much).
万分（非常）感谢.
Please accept ( I wish to express )my sincere (grateful) (profound) appreciation for
请接受（致以）真挚的（衷心的）（深切的）感谢.
I sincerely (deeply) (warmly) appreciate ...
我真挚的（深深的）（热情的）感谢.
I am very sincerely (most) (truly) grateful to you for ...
为了……,我非常真挚的（深深的）（真诚的）感谢您.
There is nothing more important (satisfying) (gratifying) to me than to receive one of your letters.
再也没有比收到您的来信更使我觉得重要（快慰）（感激）了.
It was good (fine)(charming)(thoughtful)of you...
承蒙好意（美意）（盛情）（关心）……
It was nice(characteristically thoughtful) (more than kind) of you...
承蒙好意（特别关心）（十二分好意）……
At the outset,I want to thank you for your kindness to me and for your compliments.
首先,我要感谢您对我的友爱和问候.
Believe me,I am truly grateful for...
我确实真诚地感谢你……
We were deeply touched by ...
……使我们深受感动.
It is a hopeless(definite)(positive)understatement to say that I am deeply (sincerely)(truly)grateful.
这就是说“我深深的（真挚的）（真诚的）感谢”远不足以（不能确切）（不能明确）表达我的谢意.
We are indebted to you...
我们感谢你……
I regret very much that I did not have an opportunity to thank you personally for ...
未能面谢,深表遗憾