Rated 5 out of 5 stars

Great add-on! Thank you! I have one strange question...How can I display contacts in the new message window (To: or Cc: or Bcc fields) as is shown in your last image above?

This review is for a previous version of the add-on (2.5.2).  This user has a previous review of this add-on.

This just for the inline reply only. The new message window remains the same, the addon doesn't touch it. However, the addon has a hidden feature (Ctrl-Shift-N) that gives you the possibility of using the inline reply editor for composing a new message, possibly in a tab.