英文句子錯與對? 24.04

I supposed the sentences should be as follows:
1) Are the sentences listed below correct?
The meaning of sentences of 2) & 3) is the same but it should be:
2) Please find the delivery order (DO) enclosed for your reference. Please sign back and return.
3) Enclosed herewith our DO for your reference and please feel free to sign back and return.
4) Details are as follows: / Details are listed in the following:

1)are it correct below sentences? Are the following sentences correct?
2)Please find enclosed delivery order for your reference and please sign back by return. Please find enclosed D/O No.xxx & kindly sign and return one copy.

3)Enclosed please find our DO for your reference and please sign back. Enclosed please find our D/O No.xxx. Please sign & return one copy.

4)detail to follow. Details to follow. or: details will follow.
Note: 1/ are it 肯定是錯, 你混合了單/複數, 應是: is it 或 are they...
2/ D/O is an official document, 你不須說 for your reference. 及應打出D/O number.
3/ Same as 2/.

1. Are the sentences below correct ?
2. Correct.
3. Correct.
4. Correct. (Better add "s" after detail = details)