向上司/客人道歉

Dear Mr. Chan,

Please accept my apologies for my mistake. I know that this mistake must have caused a lot of problems. I can guarantee, this won't happen again.

Regards,
Tim

親愛的陳先生,

請接受我為我的錯誤道歉。 我知道這個錯誤肯定會引起很多問題。 我可以保證,這樣的事情不會再發生了。

Regards,
Tim