I cannot refrain from expressing my admiring appreciation of——
You are to be congratulated upon the——
I wish to congratulate you, and express my appreciation of——
Will you permit me to make an acknowledgment of appreciation to you for——
Permit me to make appreciative acknowledgments of——
Please accept my congratulations upon your——
Since the news of the joy that has happened to you reached me, I have been anxious to write you a word of congratulation
I congratulate you on the very fortunate opportunity which presents itself
I had the great pleasure of hearing that——
I take this opportunity of assuring you that——