Thunderbird doesn’t appear to have a built in way to do this, but you can do it with other tools vailabile in Ubuntu 20.

  • Select email in Thunderbird inbox
  • Export as .eml (File > Save as > File)
  • Open the .eml file in a text editor
  • Edit the email to correct any formatting or add any missing details

  • Convert the email to HTML with MHonArc (Thanks to 3wordchant on Ask Ubuntu for the tip.)

      sudo apt install mhonarc
  mhonarc -single file.eml > file.html
  • Open the .html file in a text editor

  • Edit the HTML to remove the headers

    • Select all lines inclusive

      • from <!--X-Head-Body-Sep-Begin-->
      • to <!--X-Head-Body-Sep-End-->

    • Delete selected lines

  • Open .html file in Firefox
  • Print and save as PDF