[Mimedefang] Invalid "mimedefang.pl -structure" output and virus scanning behaviour

[David F. Skoll]

On Mon, 1 Mar 2004, Steffen Kaiser wrote:

> This makes three weaknesses in the MIME::Tools so far.

I disagree.  There are an infinite number of these kinds of "weaknesses"
(a poster e-mailed me one off-list in the hopes that I'd code a workaround.)

The reason is that there are an infinite number of ways to mangle MIME, and
it's a futile effort to write hacks to work around them.

The *ONLY* safe way to handle these situations is to canonicalize every
message that passes through your mail server by calling "action_rebuild()"
in filter_end.

Please note that I will not accept suggestions or patches to make MIMEDefang
parse broken MIME, for two reasons:

1) The upstream maintainers of MIME::tools and Mail::Tools will likely not
accept the patches.

2) Fixing one of the infinite "weaknesses" will leave infinity minus one
left to be fixed.

Bottom line:  If you are worried about this, you *must* canonicalize
e-mail.  It's the only secure solution.

Regards,

David.