[Mimedefang] Re: Unsafe file types

David Meissner DavidM at instantservice.com
Tue Dec 2 13:56:36 EST 2003


Following your philosophy, that email exists to communicate and admins
should refrain from interfering with that communication as much as possible,
then the question arises, why try to stop spam or viruses at all? In fact, a
case could be made that email filtering is ethically questionable. People
who send spam are trying to communicate; the content may be fraudulent or
morally offensive, but why is it up to system administrators to pass
judgement on it? Your logic suggests that admins should get out of the way
and let all mail go to the end user, and leave it up to them to filter spam
and block viruses.

The problem is that this isn't practical. Spam/viruses/worms are in fact a
massive denial-of-service attack, and until a better solution comes along,
mail filtering is the only way to deal with it. We have already decided to
inspect private email to determine whether it should be delivered or not. We
therefore have a responsibility to filter efficiently, with a minimum of
false positives. ("First, do no harm"). Blocking executable attachments
meets this requirement; it is efficient, and the false positive rate is low.
That is the best we can do for now.

-David Meissner


> Now, as for the other comments regarding my original email. I 
> certainly understand the attitude that you have to lock 
> things down tightly because you're personally responsible for 
> every desktop and the internel network in general. But you 
> have to understand that people have to get their jobs done. 
> No matter how tight you clamp down on your email, they will 
> find ways to transfer the documents and files they need to. 
> {thinking back to the era when there were no attachments on 
> email and uuencode was the perfered method of choice, perhaps 
> we'll be there again}. But the trouble is, the more hoops 
> they jump through, the less productive they'll be.
> 
> Anyway, it looks like I'm alone here ;)
> 
> -lee



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