● 收信

我们收到了您1998年4月14日的来信。
We have received your letter of April 14, 1998.
We have received your letter dated April 14, 1998.

我们收到了您的咨询函，非常感谢。
We thank you for you inquiry.
We have received your letter and thank you for your inquiry.

我们非常高兴从您的来信中获悉……
We are pleased to learn from your letter...
From your letter we have learned that...

我们收到了您1998年5月23日的来函查询，非常感激。
We are grateful for your inquiry of May 23,1998.

我们已经收到了您1998年6月6日的来信。
This is to acknowledge your letter of June 6, 1998.

● 回信

我非常愉快地回复您1998年8月18日的来函查询。
We are pleased to respond to your inquiry of August 18, 1998.
We are pleased to answer your letter of August 18, 1998.

以下是就您1998年10月21日来信的回函。
We are writing in response to your letter of October 21, 1998.
We are writing with reference to your letter of October 21, 1998.

这是对您1998年10月29日来信的复函。
This refers to your letter of October 29, 1998.

这是对您1998年11月4日来信给予的答复。
This is in response to your letter of November 4, 1998.

● 从来信中得知

我们高兴地从您的来信中得知……
We are happy to learn from your letter that...
From your letter we have learned that...

我们很遗憾地从您的信中得知……
We regret to learn from your letter that...
We are really sorry to learn from your letter that...

我们为我们的差错向您表示真诚的歉意。
We would like to offer our sincere apologies for the mistake. *“从内心发出的歉意”，用sincere apologies表示。

得知……真是太好了。
It is nice to know that...
It is nice to learn that...
It is nice to hear that...

为……我们很遗憾。
It is regretted that...
It is regrettable that...