(In reply to comment #100)
It works, but as said we need either the Mnenhy or Enigmail extension installed and the ReplyToList extension.
But about the button, I think that it would be better to automatically transform the Reply button to a ReplyToList button and adding a small arrow (like for the print button) which would allow to just "Reply To" (and possibly remember this behavior).
(In reply to comment #100)
It works, but as said we need either the Mnenhy or Enigmail extension installed and the ReplyToList extension.
But about the button, I think that it would be better to automatically transform the Reply button to a ReplyToList button and adding a small arrow (like for the print button) which would allow to just "Reply To" (and possibly remember this behavior).