This is not a thunderbird issue. please open a bug against gnome(maybe gnome-trash if possibile). If you cd into the trash dir. and remove it from terminal it should delete it.
** Changed in: mozilla-thunderbird (Ubuntu) Status: Incomplete => Invalid -- Can't empty trash https://bugs.launchpad.net/bugs/314227 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs