We developed a new email client which runs on the browser and is not dependent on a particular server, based on the Unhosted web application architecture. The client can connect to any standard mail server directly from the browser, using IMAP and SMTP protocols so that the user is not limited to the webmail clients provided by various email service providers. As our client runs in a browser, it is independent of the operating system. It provides a uniform user experience on any mail system. As a part of our unhosted email client, we have developed a browser extension to allow HTML5 clients to connect to IMAP and SMTP servers. Using this extension, developers may introduce new e-mail clients which are both server and operating system independent. Our client application also provides offline features so that the user can load the application and read/create mail even if he/she is not currently connected to the Internet.