Gmail

Gmail is a free, advertising-supported email service provided by Google.[1] Users may access Gmail as secure webmail,[2] as well via POP3 or IMAP protocols.[3][4] Gmail was launched as an invitation-only beta release on April 1, 2004[5] and it became available to the general public on February 7, 2007, though still in beta status at that time.[6] The service was upgraded from beta status on July 7, 2009, along with the rest of the Google Apps suite.[7][8]

With an initial storage capacity offer of 1 GB per user, Gmail significantly increased the webmail standard for free storage from the 2 to 4 MB its competitors such as Hotmail offered at that time.[9] Individual Gmail messages, including attachments, may be up to 25 MB,[10] which is larger than many other mail services support. Gmail has a search-oriented interface and a "conversation view" similar to an Internet forum. Gmail is noted by web developers for its pioneering use of AJAX.[11] Gmail runs on Google GFE/2.0 on Linux.[12][13][14] As of October 2011, it had 260 million users worldwide.