The Email Game, also known as the Email Challenge, allows users to engage in friendly competition with friends. You can invite others to participate by sharing your game session or inviting them through various means provided by the app, depending on its features at the time. The purpose of these invitations is to create an enjoyable environment where players can challenge one another to effectively manage their inboxes while competing for faster completion times. This adds a social element to the experience and motivates participants to improve their email management skills in a fun way. Users should check the latest information on the app's official website or their current page for specific details on how to invite friends, as updates and new features may have changed since the last information was available.