Generally, in Thunderbird if you select text prior to carrying out an action, the action is applied to just that text. So, for instance, you can selectively quote from a message when forwarding it. If you select all the message text using ctrl+a before you print, I'd hope that just the selected text would go to the printer.

This might help. But I suspect it will print the headers anyway.

You could just select the body text from the original message and copy and paste it into a new document using Notepad or Wordpad, then print that.

You could send yourself a copy of the message (add yourself to the Bcc list), and print the copy that comes back to your Inbox. Then this correspondent will see exactly the same as all those who received it via email. This copy won't have all the Bcc addresses in it, and will probably print more predictably and consistently. The compose window isn't entirely wysiwyg, and features such as tables and frames appear differently.

Thank you. I will try that sending it to myself bit. I was surprised when all the addresses printed out as I thought that was the point of bcc! :) Regards

re :I was surprised when all the addresses printed out as I thought that was the point of bcc!

No...you are using your copy of the sent email so obviously all the email addresses are visible.

Select the sent email so you can read contents in Message Pane. Highlight all the text. 'Menu icon' > 'Print' > 'Print Preview' This hsould show only the highlighted text. Then you can click on 'Print' button.