Gmail is a free, advertising-supported email service developed by Google. Users can access Gmail on the web and through the mobile apps for Android and iOS, as well as through third-party programs that synchronize email content through POP or IMAP protocols. Gmail started as a limited beta release on April 1, 2004. It exited beta status on July 7, 2009.
Gmail at launch had an initial storage capacity offer of 1 gigabyte per user, a significantly higher number than the 2 megabytes of storage its competitors such as Hotmail offered at that time. Today, the service comes with 15 gigabytes of free storage. Users can receive emails up to 50 megabytes in size, including attachments, while they can send emails up to 25 megabytes. In order to send larger files, users can insert files from Google Drive into the message.
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.
Google has stated that “all users of email must necessarily expect that their emails will be subject to automated processing […] Just as a sender of a letter to a business colleague cannot be surprised that the recipient’s assistant opens the letter, people who use web-based email today cannot be surprised if their communications are processed by the recipient’s ECS [electronic communications service] provider in the course of delivery.” Google also claims that Gmail refrains from displaying ads next to potentially sensitive messages, such as those that mention race, religion, sexual orientation, health, or financial statements.
As of February 2016, Gmail has one billion active users worldwide, and was the first app on the Google Play Store to hit one billion installations on Android devices. According to a 2014 estimate, 60% of mid-sized US companies, and 92% of startups, were using Gmail.