Printing Tools NG for TB 78 is under development:

https://github.com/cleidigh/printing-tools-ng/issues/13

I don't know of a way to auto print in the background, but it is possible to export all messages in a folder to a single text file, if that offers any advantage.

Thank you for your assistance. This will work quite well.

I only need the main content of the email message body to be parsed into the text file, are you aware of a way to configure the tool to only extract the pertinent information and not all the filler content such as email signature etc?

I don't know of a way to make the add-on parse messages, but you could ask the developer. I see there are many references to email parsing, but most of them are stand-alone programs that operate outside of email clients.