Re: Spam filtering

On Wed, 28 Oct 2015 08:27:51 -0400
Al Zick <[email protected]> wrote:

> Is anyone running spam filtering on a 68k system?

No. But I don't think that the host system matters for your question, apart
from the fact that you need something which requires only few resources.

Maybe you should ask in netbsd-users to increase the chances for a reply.


> Right now, I am looking for any solution to all the spam I am getting.

I'm already rejecting spammers at the mail server, which is a NetBSD system
running Postfix. Most spam comes from dynamic IP addresses (usually Windows
PCs infected by a Virus or Trojan), so I'm generally blocking those. A real
mail server should have a static IP and a name server entry.

Postfix smtpd has the "smtpd_client_restriction" option. From my main.cf:
smtpd_client_restrictions = permit_mynetworks,  permit_sasl_authenticated, check_sender_access hash:/etc/postfix/sender_access check_client_access regexp:/etc/postfix/client_restrictions, reject_unknown_client

In "client_restrictions" I have some generic rules as well as a black- and a
white-list. Some generic rules:

# [rule 1] *999-999-*.
# ex: 12-207-82-236.client.mchsi.com
# ex: d36-41-37.home1.cgocable.net
# ex: host26-28-static.4-79-b.business.telecomitalia.it
/^[^\.]*[0-9]+-[0-9]+-.*\..*$/                  450 may not be mail exchanger 1
#
# [rule 2] *-999-999*.
# ex: ds-nat-128-100.datasvit.net
# ex: host-157-010.consiagnet.it
/^[^\.]*-[0-9]+-[0-9]+.*\..*$/                  450 may not be mail exchanger 2
#
# [rule 3] *999.999.*.
# ex: p62.246.31.47.tisdip.tiscali.de
# ex: 62.117.158.210.dyn.user.ono.com
# ex: 219.57.broadband9.iol.cz
/[0-9]+\.[0-9]+\.[^0-9]+.*\..*$/                450 may not be mail exchanger 3
#

etc...

The remaining spam is then filtered by the individual mail-clients.

-- 
Frank Wille