The email style message view is the same chat content in a different UI. It's a full screen view that looks vaguely like Outlook - message threads are listed on

The email style message view is the same chat content in a different UI. It's a full screen view that looks vaguely like Outlook - message threads are listed on the left and the majority of the screen is dedicated to reading the messages. It's much nicer to use for browsing your message history or writing something more detailed without having to mess around with tiny chat windows. There is also https://www.messenger.com/ https://www.messenger.com/, which is a similar UI but available as standalone site.