Postage stamps were introduced in Britain in 1840 as a way of showing that the sender had paid for the letter to be delivered.1840年,英国开始使用邮票,以表明寄信人已付邮资。
The letter came back with "return to sender - not known at this address" written on it.信被退了回来,上面写着“退还寄信人——此地址查无此人。”