文法的問題

文化上,如用pp(present perfect tense)你不算錯,最好加時間指標eg. I have just received your letter (表示你剛剛收到他的信). Or 用 simple past tense, eg. I received your letter two days ago. 在 Tense 上是有分別.

但你系錯在書信上做開頭的用法. 給你一般書信例子:

(給friend 的 私人書件)
1. I am glad to receive your letter.
2. Thank you for your letter dated 10 August 2007 that I received yesterday.
3. Received your last letter with thanks.

(商業書件)
1. Referring to your letter date 10 August 2007 that we received on 20 August 2007, ……….
2. Thanks for your letter dated 10 August 2007 that we received on 20 August 2007.
3. In receipt of your letter dated 10 August 2007, ………..
4. We acknowledge receipt of your letter dated 10 August 2007.

if you just want to express that you received someone's letter, you just use Past tense " I received your letter"
but if you want to use PP, you have better to state the time, period\
e.g. I have recieved your letter for three days

I have received your letter - did not specify the time received.
PP, I think you mean simple past, RECEIVED
For example, I received your letter yesterday OR I received your letter on August 16.

2007-08-19 19:54:03 補充：
你用這句開頭, 當然是錯了. In english usage or commercial english, we use:Thank you for your letter .........