Snail mail and smail (from snail + mail) — named after the snail with its slow speed — is a retronym that refers to letters and 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, email.
It is also known, more neutrally, as paper mail, postal mail, land mail, or simply mail and post. An earlier term of the same type is surface mail, coined retrospectively after the development of airmail. This happened between the 1970s and 1990s.
Snail mail penfriends or penpals are those that communicate with one another through the postal system, rather than on the Internet which has become the more common medium.
Some online groups also use paper mail through regular gift or craft hot topics. In some countries, services are available to print and deliver emails to those unable to receive email, like people with no computers or Internet access.
Similar terminology was used in the 1840s to contrast the already-operating postal mail with the new telegraph. The Philadelphia North American stated: "The markets will no longer be dependent upon snail paced mails".
The term "snail mail" appears as early as 1942 in the headline of a news article about slow mail delivery. The term also appears as a sub-headline in a 1951 news article.
The term snail post has much earlier usage, as in an article published 1843, in Fraser's Magazine for Town and Country (page 656). This was a humorous British reference to the German 'Schnell (fast) Post', which was notoriously slow.
The term snail mail was used by the U.S. Post Office in magazine advertising in the mid to late 1960s to encourage use of zip codes. Ads for zip code use appeared in many issues of LOOK, Life, and the Saturday Evening Post magazines and displayed a caricature of a large snail outfitted as a letter carrier, with the term "Snail Mail" in bold lettering.