The article introduces Caniemail.com, a website that tracks the support of various email clients for different HTML and CSS features, similar to Can I Use for web browsers. The website provides a comprehensive list of email clients and their support for various features, as well as a scoreboard ranking the clients based on their support. The website aims to help email developers and designers determine which features are supported by different email clients. The website is based on data contributions from the email geeks community on GitHub.