This solution breaks DKIM - it inserts new postfix headers. You can do the same thing in Thunderbird by going into the config editor and adding your own "x-ms-r

This solution breaks DKIM - it inserts new postfix headers. You can do the same thing in Thunderbird by going into the config editor and adding your own "x-ms-reactions: disallow" headers as per https://kb.mozillazine.org/Custom_headers https://kb.mozillazine.org/Custom_headers