We don't have Fedex account. You know only those companies who have Fedex account can send by freight collect. Otherwise it's very difficult for us to send out.
(最后一句建议改成: So we can't send by freight collect 我们无法用到付来寄). 因为商务英语需要简短明确,不能模棱两可. 但可以建议他先把运费付给你们,你们再预付运费用Fedex寄.可这样说: May I suggest that you pay us the freight charge first and we prepay to send by Fedex?