If you are trying to disable Thunderbird's wrapping of plain text emails, this can be done by setting the auto-wrap line length to zero. Find on the menus, Edit -> Preferences. Switch to the "Advanced" panel, then on the General tab is a button to Open the "Config Editor". Agree to be careful when prompted. (screenshots taken on Fedora)  Filter the preferences by "wrap", and set both editor.htmlWrapColumn and mailnews.wraplength to zero. Close the dialog (takes effect immediately).  |