Gmail

GmailShort for Google mail, Gmail is a free service provided by Google that enables users to send and receive e-mail over the Internet. Gmail was initially thought of as a joke because it was announced April 1st, 2004. What initially made Gmail unique and still makes it unique today compared to other similar services is the ability to store several gigs of e-mail, meaning almost all users never have to worry about e-mails being prematurely deleted or the inability to receive e-mails because they have exceeded their quota. The Gmail service also allows users to have a Gmail account for up to nine months of inactive use, whereas other similar services require users to log in at least once every 30 days.

Also see: E-mail, ESP, Google, Hotmail