1. I am writing to confirm /enquire/inform you…

我寫信時要確認/詢問/通知你…

2. I am writing to follow up on our earlier decision on the marketingcampaign in Q2.

我寫信來追蹤我們之前對于第二季度營銷活動的決定。

3. With reference to our telephone conversation today…

關于我們今天在電話中的談話...

4. In my previous e-mail on October 5…

先前在10月5日所寫的信…

5. As I mentioned earlier about…

如我先前所提及關于…

6. As indicated in my previous e-mail…

如我在先前的信中所提出…

7. As we discussed on the phone…

如我們上次在電話中的討論…

8. From our decision at the previous meeting…

如我們在上次會議中的決定…

9. As you requested/per your requirement…

按照你的要求…

10.In reply to your e-mail dated April 1，we decided…

回答你在4月1日寫的信，我們決定…