To get the full text of an HTML message from TheBat email software you can do the following:

  1. Message -> SaveAs -> Save as Type – I
  2. Select Unix Mailboxes[*.mbx]
  3. Open the file in your preferred editor, then simply cut and paste.

For The Bat! v1.53bis:

  1. Select the message in question
  2. Click on the “Messages” menu
  3. Select “View Source”
  4. Alternatively, you may push F9 instead of the last two steps.