ccao@??? said:
> I know this is discouraged on the Exim spec because issues with MINE
> content. I want to modify Nigel's system filter to just add some
> warning text at the beginning of the message and deliver it anyways.
You mean MIME (and digital signatures).
[Off topic slightly, here's part of a set of stuff I sent to someone
last week who was after consultancy to add footers to mail in the MTA:-
Adding footers to mail in the MTA is wrong because:-
1. It breaks digital signatures. As these became legally binding
yesterday thats particularly bad timing
2. It breaks MIME encoding
3. It is illegal under German and Dutch law to change the body of
a mail message in transit. It might potentially be illegal in
the UK under European law.
4. Since the delivered message body was produced by the MTA (not the
originator since you modified it), the MTA operator could
potentially be sued for any content.
5. Some mail clients (old versions of MS outlook) crash if the message
body of an incoming MIME message has been tampered with.
6. It is not the job of an MTA to modify content.
]
Anyhow, this *cannot* be done in an exim system (or user) filter.
Thats cannot as in there is *no* facility for doing anything that
modifies the body of the message. Closest you can do is add a header.
How would you stand legally if you added a phrase at the start of the
message saying "this message has a virus", but the body content was
text/html (ie your text vanished because it was outside the relevant
markup), and the virus - a javascript or infective html link - trashed
the recipients machine? You know of this but still delivered an
active payload????
If you have to tamper with message content consider a transport filter.
But then again, don't!
Nigel.
--
[ - Opinions expressed are personal and may not be shared by VData - ]
[ Nigel Metheringham Nigel.Metheringham@??? ]
[ Phone: +44 1423 850000 Fax +44 1423 858866 ]
