[Mimedefang] Double From: lines in email

[Richard Laager]

On Tue, 2006-02-21 at 11:08 +0100, Sleeuwenhoek J. wrote:
> This doesn't stop emails with double From: headers from forging internal emailaddresses. Does anyone know of a method to stop this from happening. Currently I'm preventing this with a custom spamassassin rule, but I like to log this with MD.

Open the HEADERS file and run over all the lines. It's one header per
line, guaranteed (so you don't need to handle the wrapping yourself). If
you find a From: header, do your filtering.

This makes me thing... Are double From: headers a good indicator of
spam?

Richard