Email - Spelling

Spelling

Electronic mail has several English spelling options that occasionally prove cause for vehement disagreement.

• email is the form required by IETF Requests for Comment and working groups and increasingly by style guides. This spelling also appears in most dictionaries.
• e-mail is a form previously recommended by some prominent journalistic and technical style guides. According to Corpus of Contemporary American English data, this is the form that appears most frequently in edited, published American English writing.
• mail was the form used in the original RFC. The service is referred to as mail and a single piece of electronic mail is called a message.
• eMail, capitalizing only the letter M, was common among ARPANET users and the early developers of Unix, CMS, AppleLink, eWorld, AOL, GEnie, and Hotmail.
• EMail is a traditional form that has been used in RFCs for the "Author's Address", and is expressly required "for historical reasons".
• E-mail is sometimes used, capitalizing the initial letter E as in similar abbreviations like E-piano, E-guitar, A-bomb, H-bomb, and C-section.

There is also some variety in the plural form of the term. In US English email is used as a mass noun (like the term mail for items sent through the postal system), but in British English it is more commonly used as a count noun with the plural emails.