"However, a closer look reveals that the problem isn't with Linux and Hotmail's interoperability, but with how Hotmail handles browsers with "UserAgent" settings that it doesn't recognize. The User-Agent string is sent by your browser to the Web server hosting the site you're visiting. This character string, at the least, identifies your Web browser to the server. It usually also contains optional details, which are called tokens. These typically include your operating system, language, and hardware. "