[Mimedefang] recursively removing headers from forwarded attachments

[Joseph Brennan]

>> I'm using MIMEDefang to remove headers from outgoing mail
>> which would otherwise reveal details of my organization's
>> internal network, virus scanner, etc.
>
> This seems like a misplaced trust in "security by obscurity" that will
> make it harder tracking down eventual mail problems (including delivery
> problems and powned or infected local hosts).


It makes it hard for hosts to distinguish your mail from botnet spam.
Normally, if headers indicate a message was created by a popular mail
client, one expects to see at least one Received hop in there, where
the client gave it to its smtp server.  One technique to detect fakes
is to notice the lack of Received headers.

Joseph Brennan
Columbia University Information Technology