On Wed, 4 Feb 2004, Jon Gabrielson wrote:
> About 90% of the email I receive is spam. Spamassassin
> does a great job of blocking this spam, but it is still consuming
> a huge amount of bandwidth.
>
> My current ideas to prevent this are:
>
> 1) retire existing email addresses
> (a very big headache)
Only real effective spam reducer. Get a new address and never give
it out. (Of course the dictionary attackers will still get you ;)
> 2) reply to all spam with fake bounces
> (most spam has fake addresses and
> this just increases bandwidth usage)
Won't make -any- difference, spammer engines (open relays, open proxies,
PC-trojans) ignore them.
> 3) switch from postfix to exim, so that I can block spam at smtp time.
> (If someone has tried this, does this have any effect on the
> total amount of spam?)
This does not reduce network bandwidth as you still have to "pull in"
the whole message to actually run the rules on it. The SMTP reject is
returned after you've received the whole message DATA, instead of the
final "250 message accepted"
It will save on disk-space and your time looking at the garbage.
(IE reduces the amount of spam that is apparent to you).
The only other way to actually reduce the bandwidth is something like
sendmail's "access-db" control. IE a block-list of hosts, IP adresses,
e-mail addresses that you use to drop the connection at the beginning
of the SMTP conversation. (even better, a router IP filter to keep
those -nasty- packets from even getting to your network ;).
> Does anyone know of any other way to potentially reduce the initial
> pre-filtered amount of spam?
Yes, disconnect your network cable. ;)
--
Dave Funk University of Iowa
<dbfunk (at) engineering.uiowa.edu> College of Engineering
319/335-5751 FAX: 319/384-0549 1256 Seamans Center
Sys_admin/Postmaster/cell_admin Iowa City, IA 52242-1527
#include <std_disclaimer.h>
Better is not better, 'standard' is better. B{
