This is a simple add-on for Thunderbird which deselects a selected message when clicking in an empty area of the thread pane.
It works with TB45.*
開發者留言
This add-on is based on 18 lines of code found in After Delete which has been disabled because of apparent abandonment by the developer. The original more complex add-on was developed by Michael Buschbeck. The listed developer "Kevin" picked it up but failed to maintain it.