The idea for Gmail was developed by Paul Buchheit several years before it was announced to the public. The project was known by the code name Caribou. During early development, the project was kept secret from most of Google’s own engineers. This changed once the project became better and better, and by early 2004, almost everybody was using it to access the company’s internal email system.
Gmail was announced to the public by Google on April 1, 2004 as a limited beta release.
In November 2006, Google began offering a Java-based application of Gmail for mobile phones
In October 2007, Google began a process of rewriting parts of the code that Gmail used, which would make the service faster and add new features, such as custom keyboard shortcuts and the ability to bookmark specific messages and email searches. Gmail also added IMAP support in October 2007.
Gmail exited the beta status on July 7, 2009.
Prior to December 2013, users had to approve to see images in emails, which acted as a security measure. This changed in December 2013, when Google, citing improved image handling, enabled images to be visible without user approval. Images will be routed through Google’s secure proxy servers rather than the original external host servers. MarketingLand noted that the change to image handling means email marketers will no longer be able to track the recipient’s IP address or information about what kind of device the recipient is using. However, Wired stated that the new change means senders can track the time when an email is first opened, as the initial loading of the images requires the system to make a “callback” to the original server.
In June 2012, Google announced that Gmail had 425 million active users globally.
In May 2015, Google announced that Gmail had 900 million active users, 75% of whom were using the service on mobile devices.
In February 2016, Google announced that Gmail had passed 1 billion active users.
In the business sector, Quartz reported in August 2014 that, among 150 companies checked in three major categories in the United States (Fortune 50 largest companies, mid-size tech and media companies, and startup companies from the last Y Combinator incubator class), only one Fortune 50 company used Gmail – Google itself – while 60% of mid-sized companies and 92% of startup companies were using Gmail.
In May 2014, Gmail became the first app on the Google Play Store to hit one billion installations on Android devices.