The main answer of Reading the mail content of an mbox file using python mailbox shows how to display the content of an email from a .mbox file:
if message.is_multipart():
content = ''.join(part.get_payload(decode=True) for part in message.get_payload())
else:
content = message.get_payload(decode=True)
However this does not show the "full original source" of the email ; I mean what we can have in nearly all webmails when clicking "Show original message":
Delivered-To: ...
Return-Path: ...
...
How to get this with Python mailbox
?