Gmail

Gmail is a free email service developed by Google. It was launched on April 1, 2004, initially by invitation and later opened to the public. As part of Google's account ecosystem, Gmail can be accessed through web browsers and mobile apps on Android and iOS. It integrates with other Google services such as Calendar, Drive, and Contacts and supports single sign-on for Google accounts.

Its interface emphasizes conversation threads, label-based organization (instead of traditional folders), powerful search with operators, and filters that automatically categorize messages. Gmail provides categories such as Primary, Social, and Promotions, along with features like snooze, scheduled send, and smart replies. It offers offline access through the Chrome browser and supports multiple languages and accessibility options.

For protocol and security, Gmail supports POP3, IMAP, and SMTP for client access, with TLS encryption in transit. It supports two-factor authentication and OAuth 2.0 for secure sign-in. Spam and phishing protections are built into the service, and Google Workspace administrators can enforce data- and access-control policies for business accounts.

Storage has grown from 1 GB at launch to 15 GB of free storage shared across Gmail, Google Drive, and Google Photos, with paid plans available through Google One or Google Workspace for additional space. Gmail remains one of the most widely used email services worldwide, serving consumer and business users and offering a developer API (Gmail API) for programmatic access.