How do you stop outgoing spam?

Tue Sep 17 16:30:36 UTC 2002

At 10:26 AM -0700 2002/09/15, Dave Crocker wrote:

>  2. The issue with email is authentication, not privacy.
>  Authentication can be achieved can be achieved easily over port
>  25, without encryption.  Hence, blocking port 25 blocks
>  legitimately validated email, as well as possible spam.

	True enough.  However, there are no intelligent transparent 
proxies that I know of which will allow authenticated and/or 
link-encrypted port 25 connections through to the indicated site, and 
shunt the non-authenticated/non-encrypted sessions to the side. 
Since this information is only available at the IP level, this is not 
something you can fix inside the SMTP MTA -- the critical information 
is destroyed before then.

	I imagine if you could get cisco (and other vendors) to fix their 
transparent proxy server software to be more intelligent, that would 
fix the problem.

-- 
Brad Knowles, <brad.knowles at skynet.be>

"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety."
     -Benjamin Franklin, Historical Review of Pennsylvania.

GCS/IT d+(-) s:+(++)>: a C++(+++)$ UMBSHI++++$ P+>++ L+ !E W+++(--) N+ !w---
O- M++ V PS++(+++) PE- Y+(++) PGP>+++ t+(+++) 5++(+++) X++(+++) R+(+++)
tv+(+++) b+(++++) DI+(++++) D+(++) G+(++++) e++>++++ h--- r---(+++)* z(+++)