Google Mail (Gmail).
Gmail was launched as an invitation-only beta release on April 1, 2004 and it became available to the general public on February 7, 2007, though still with beta status. As of July 2009[update], it has 146 million users monthly. The service was upgraded from beta status on July 7, 2009, along with the rest of the Google Apps suite.
With an initial storage capacity offer of 1 GB per user, Gmail significantly increased the webmail standard for free storage from the 2 to 4MB its competitors offered at that time. The service currently offers over 7350 MB of free storage with additional storage ranging from 10 GB to 400 GB available for $20 to $500 (US) per year.
Gmail has a search-oriented interface and a "conversation view" similar to an Internet forum. Software developers know Gmail for its pioneering use of the Ajax programming technique.
Spam filter
Gmail's spam filtering features a community-driven system: when any user marks an email as spam, this provides information to help the system identify similar future messages for all Gmail users.
