Filter do auto-answer by template but sent msg is malformed by change UTF-8 coding and block build-in pictures.
v147.0.1 (64bit) = latest I create a template. Template used by "send a new e-mail from template" works fine and send with text and pictures. All Good.
I use a Filter that sends an auto-reply from a Template. Sent message have wrong coding (Poland chars are replace to some strange characters) and no picture in it, at bottom of e-mail are some codes.
Seams of BUG in Thunderbird, a many years ago was z bugzilla for Mozilla products, now I found only that forum.