Close On Reply 1.1
Close window or tab when you reply to a message.
This add-on has been preliminarily reviewed by Mozilla. Learn more
This add-on is not compatible with your version of Thunderbird because of the following:
Add extra features and styles to make Thunderbird your own.Close
This is an simple add-on that will close tab or window on reply. It might not be the best way to do it, but so far it worked fine. Fell free to change anything, or sugest a better way to do it.