This letter is too important to send by mail.

这封信太重要了，不能用邮递方式送去。

A loaf of bread, a terrestrial globe, a plastic skeleton and a hamburger. Is there anything you can't send by mail?

一块面包，一个地球仪，一个塑料骨架和一个汉堡包，还有什么邮局不能寄送的东西么？

For example, it would be possible for you to send by mail train your Sunday lunch leftovers for your friend to eat for his Sunday lunch.

比如，对你来说你可以用邮政列车把你周日午餐的剩饭菜寄给你的朋友做为他周日的午餐。

We can send a gift card by mail if you prefer.

如果您愿意，我们可以邮寄礼品卡。

We'll send out the manuals this afternoon by express mail entirely at our cost, and the manuals should arrive tomorrow or the day after at the latest.

我们将在今天下午通过快递将手册全部寄出，邮费由我们负责，这些手册最迟明天或后天可以送到。