·“Electronic mail,” as a phrase I have usage of Business Week going back to 1975. Am interested in earlier usage, particularly in publications aimed at business or the general public.
·“email” or “e-mail” as a word. A Google Groups (formerly Deja News) archive of a May 1981 post suggests that the Compuserve email program might have been called EMAIL.
The _Oxford English Dictionary_ is always worth a look for this kind of query. The team who deal with these things put a lot of work into tracing authenticated uses as far back as they can (working to a fairly strict standard of authentication); a typical word entry gives the first known usage of any kind, followed by a series of later ones to illustrate the process of popularisation and/or subtle changes of meaning. Thus, for "electronic mail", they give 1959 _Appleton [Wisconsin] Post-Crescent_ 2 Nov. a6/4 Postmaster General Summerfield plans split-second electronic mail. 1969 _Law & Contemp. Probl._ 34 447 Facsimile newspaper or electronic mail delivery. 1977 _Science_ 18 Mar. 1161/1 Electronic mail can be originated by conventional means (typewriter, handwriting, printing). 1978 _Globe & Mail_ [Toronto] 8 Dec. 4/5 The world's first completely electronic mail service is scheduled to start operating in Canada this February. And for "email"/"e-mail", 1979 _Electronics_ 7 June 63 (heading) Postal Service pushes ahead with E-mail. This corresponds to the snippet at books.google.co.uk/books?id=xTFWAAAAMAAJ&q="e-mail"+intitle:electronics&dq="e-mail" which is enough to show that "Postal Service" is the USPS. Does anyone here have access to a back run of _Electronics_, I wonder? Perhaps surprisingly, the OED doesn't see any noteworthy changes to the circulation of "e-mail" till much later than the episode we're interested in -- 1986 -- when it appears (without scarequotes) in the _Times_ of London. It first finds "email" without the hyphen in 2005, which I suspect could easily be antedated. As a aside, the first authenticated use of "email" as a verb is as follows: 1983 Computokid in net.micro (Usenet newsgroup) 25 Aug., Young stuff interested in correspondence (via dull old paper mail) might email a letter to me to forward. As a much further aside aside, "email" is actually found in 1684, and "emayle" in 1594 -- but as a variant of "enamel". Hope this helps! James