[bogofilter] using block_on_subnets

[Tom Anderson]

From: <tallison at tacocat.net>
> What is an ASN?

It's an "IP-like" number given to a subnet of the internet with similar
external routing policies.  Thus it is more inclusive than an IP range, but
tends to be more indicative of geographic proximity or other shared
attributes.  See the links below, or do a google search for more info.

Here's a FAQ:
http://www.apnic.net/info/faq/as_faq.html

These are the RFCs:
http://www.faqs.org/rfcs/rfc1930.html
http://www.faqs.org/rfcs/rfc2270.html

Power-point-like slide show:
http://www.ripe.net/ripencc/about/presentations/APNIC-ASpolicy/

> I read through some of the description/code of spamitarium and have one
> comment.  The removal of some X-Headers could be "bad".  I love getting
> X-List headers so I can filter on my mailing lists.  It also is useful to
> keep X-Loop headers around to avoid other problems.

Don't pass the "s" option and all of the original headers will be output.  I
choose to only permit standards-compliant emails personally.  X-headers are
non-standard by definition.  Spammers may use them to try to pollute your
wordlist.  Even if they don't, in my opinion, it just adds bloat to
everywhere the email is stored and processed.  There are standards-compliant
list headers which you can enable by uncommenting this line:

#$spec_fields .=
",list-id,list-help,list-unsubscribe,list-subscribe,list-post,list-owner,lis
t-archive";

But do you really need it?  All mailing lists provide subscription
information directly in the body of each email.  Putting it in the header is
just noise.

Tom