Package: sylpheed Version: 3.7.0-8 Tags: upstream Compose windows feature the string "Compose *" after the subject in the window's title. This string effectively clips the message's subject, which is more important, in my Window's manager (xfwm4) working areas list, which includes windows, because the width of the window list is limited.
I'm going to file another bug to xfwm because of the artificial width limit, but I suspect the clipping is a Sylpheed bug.