I can either send it to you by express mail or alternatively compensate you at a reasonable price.

我可以快件寄给你，或者以合理的价钱补偿你。

Can I deliver the file by express?

我可以用快递寄送这份文件吗？

I sent the letter by express.

我这封信寄的是快递。

The letter was sent by express.

这信是用快件邮寄的。

Send it by express delivery.

以快递把它寄出。