It is wise to create two different overlays for Thunderbird.
One for the main window which covers everything that standard intags do but now you can also include the message section properly.
For the Write, Forward and Reply window you can create a second one (overlay 2) which will work in all these three windows. Make sure to tag everything you need.
When finished you can create some very fast Dragon DVC commands to automatically call up the overlay(s) when you launch the program itself or reply (or forward) to messages.
Mind you, these are (fast) DVC commands and they use milliseconds Wait times (not seconds like in Advanced Scripting):
AppBringUp "C:Your Paththunderbird.exe" 'specify the exact path to the executable
Wait 2000 'set specified wait time for your system
HeardWord "hide","numbers" 'VC sometimes shows both the overlay as well as the standard intags which is not what you want
Write new email:
Reply to email:
Saving email to disk:
HeardWord "show","numbers" 'which makes it easy to browse to the desired location
Calling up the main window overlay again is simply a matter of saying "show overlay".
Finally, closing Thunderbird and then automatically closing the (main) overlay too can be done with one simple command:
Dictating directly into Thunderbird is a major pain. You may want to look into my Speech Productivity Dictation box which is an excellent solution to this problem.