Book excerpt: Email client refers to software that allows users to access and manage their email accounts. This software enables users to send, receive and organize emails on their computers or mobile devices. Commonly used email clients include Microsoft Outlook, Apple Mail, Gmail, Yahoo Mail, and Thunderbird among others. Email clients provide users with various features such as email composition, formatting, spell-checking, email signature creation, and the ability to create folders for organization and managing emails. They also allow users to set up multiple email accounts, receive notifications when new emails arrive, and easily search for specific emails. Email clients have become an essential tool for communication in both personal and professional settings. They have significantly reduced the reliance on web-based email services and provided users with more flexibility and control over their email accounts.