請幫我改這幾句英文

I have checked up on all the letters which were received

over/in the past three months and inquired of other

colleagues whether they had received the letter you

mentioned. However, I found that we have not

received the afore-said letter from you. Could you please

post it to us again. If I receive the letter , I will/shall hand it

over to my supervisor.

I have checked all the letter the past 3 months, i have inquired about the letter of your company for my colleague too , but i find that our company didn’t receive the letter from your company. could you post the letter for our company again。If I receive the letter ,I will be hand over it to my supervisor.

I've checked all the incoming letters of the past 3 months about the letter sent from your company to my colleague, regret that I couldn't find it.
I suggest you send the letter afresh & I'll pass it to my supervisor as soon as it's received.

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I have checked all the letter(s) (in) the past 3 months and inquired my colleague(s) (about the letters), but I find that our company didn’t receive (any) letter from your company. Could you (deliver) the letter (to) our company again(?) If I receive the letter, I will be hand (it over) to my supervisor.

You can write like this:

I've checked the letters of the last 3 months, I would also ask other colleagues. I found that our company does not receive the letter of your company. Can you please send it to us? if I receive your letter, I will be transferred to our heads.

這樣寫可能會更容易明白 :

I have checked the letter over the past 3 months, I have also asked the other colleagues. I found your company does not receive our letter. You can then send it to us? If I received your letter, I will be transferred to us the person in charge.