When you have a Write window open, F9 will toggle the Contacts Sidebar on and off. It's also available in the menu in the same window under '''View|Contacts Sidebar'''. But if you're asking here, I guess you can't see a menu or toolbar either. http://chrisramsden.vfast.co.uk/13_Menus_in_Thunderbird.html As in many such lists, clicking on the label "Names" at the top, which is actually a button, will cause it to sort. A second click will sort again but in the opposite direction.