This is the exact suggestion I tried from another question w/ a word wrap issue and it didn't work. Is there any other settings in options which can affect word wrap not working? I'm not able to upload my screen shot for some reason. My settings are paragraph and variable width. *** Go to Tools|Options|Advanced|General Click on the button labelled Config Editor If there is a warning, say you'll be careful. In the window that appears, type wrap into the search box at the top. You should see these two below (amongst others) and I think they both need to be set to true. mail.compose.wrap_to_window_width mail.wrap_long_lines If either is set to false, double-click it to toggle it to true. Close the window and back out back to Thunderbird's main window. If you changed anything, I'd recommend closing and restarting Thunderbird to make sure it uses the new value of the setting.