Thunderbrowse is a free Firefox add-on that turns your humble email client into a mega gargantuan web browser. OK, just a web browser. Download and install it, and you’ll instantly gain the ability to browse the web directly from a CTRL-W prompt. It comes with a shed load of configuration options, and will even turn your message pane into a tabbed browser window when you click on a Web link in a message. Neat.
ThunderBrowse is an AMO recommended addon that provides browsing features for Thunderbird. With ThunderBrowse you can browse almost any website on the internet. Did a friend send you a link? Simply click the link and ThunderBrowse will load the page instantly right within Thunderbird, without the need to open another application. If you don’t want to surf on a page in ThunderBrowse you can easily right click and choose “Visit in Browser” and have the page launch in the system default browser or the browser of your choice.