Amazing! A Complete Template System Rated 5 out of 5 stars
This addon is wonderful. It's a total replacement for default template feature of Thunderbird and improved that idea a lot.
I was thinking about another great feature you can add to this addon:
Autocompletion similar to when you are writing a similar/exact text in a cell in LibreOffice Calculator/MS Excel. In this feature when you're typing similar text the suggested text would be shown in opposite color highlight (white text in black bg) and user can select the suggested text by pressing Enter, or just ignore it by continuing his typing.