Dear, I am using some templates in my Thunderbird 115.1.0 for windows 11 that are AUTO-sent based on certain rules/filters. ie when a revieved e-mail contains a specific word in the message a rule will reply to the message using template 1. I am now attaching a .gpx file with the template message. The message is sent as usual, but the attachement is not attached to the message (no attachement in the e-mail stored in sent-items). The message is recieved as an message with the added line: "This is a multi-part message in MIME format. --------------TwIF08u4BWQAhVjYA9nsShou Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 7bit " Also a lot of asci-characters are in the message. The strange this is: if I sent the very same template manually it all works like a charm. The message is sent with the GPX-file attached to it, and recieved with the complete and functioning attachement. This leaves me to think Thunderbird handels message automatically differently from manually. Is there any way around this? Looking forward to your response. Kind regards.