Snail mail

Snail mail or smail (from snail + mail) is a dysphemistic retronym—named after the snail with its slow speed—used to refer to letters and missives carried by conventional postal delivery services. The phrase refers to the lag-time between dispatch of a letter and its receipt, versus the virtually instantaneous dispatch and delivery of its electronic equivalent, e-mail. It is also known, more neutrally, as paper mail, postal mail, land mail, or simply mail. An earlier term of the same type is surface mail, coined retrospectively after the development of airmail.

蜗牛邮件是一个返璞词，在电子信息时代出现之前，没有电子邮件的概念，所有的邮件都可以称之为蜗牛邮件。蜗牛邮件的称呼来源于和电子邮件相比，传统邮件速度慢的特点。所有蜗牛邮件也可以叫纸质邮件、传统邮件或者普通邮件。

来看下面的例子：

It is called "snail mail " because it can be very slow , as is snail .

之所以被叫做“蜗牛”是因为它的速度很慢，好像蜗牛一般。

In the digital age , writing an old fashioned , snail mail letter to a friend will surely make his day .

在数字化时代，写一封老式的平信给朋友，绝对可以让他高兴一整天。