英语翻译感谢您的提醒.经核对,我们发现在2010年底我们已将正式的合同寄送给贵司,但尚未收到贵公司签字的合同寄回给我们.

Thank you for your remainder.
After checking,we find that we have not received the countersigned contract yet which we had sent to you at the end of 2010,would you please sign it and deliver it to us,we will arrange the payment as soon as we get the signed contract.

Thank you for the reminder. After checking, we found that in the end of 2010 we have a formal contract sent to your company, but not yet received your signed contract back to us. Can first signed the contract back to us, we will immediately arrange payment received.
可能会有些误差

According to the requirements of XX department, we need to report all 是不是翻译机的 一看就知道。 to meet the requirement of XX

Thanks for your warning. After checking, we find that we have sent you our formal contrat at the end of 2010, however, we haven't getten your returned contract yet; so could you send back the signed contract to us firstly, and then we will arrange payment at once.

Thanks for your reminding. After the check, we find at the end of 2010, we have a formal contract to send to your company, but have not yet received your company signed the contract and send back to us. Whether the signature of the contract and send back to us, we will arrange the payment receipt.