+++ /dev/null
-From: Ephraim Silverberg <ephraim@cs.huji.ac.il>
-Date: Tue, 17 Feb 1998 12:55:55 +0200
-
-We're using Exim 1.82 and have written a message filter to intercept spam
-messages that RBL doesn't catch. Since we have met with reasonable success
-since installing (and refining) the filter -- 566 genuine spam messages
-intercepted during a time period where there were 67 RBL rejections -- I
-thought that the rest of the list may be interested in reviewing our filter
-as a starting point for their own system message filter.
-
-There are a number of caveats, however:
-
-1. The suspected spam is not automatically rejected as RBL hosts are, but
- is saved to a folder that should be read/writable by the mail
- administrators. The reason for this is that the filter catches also
- some legitimate mail and these messages should be bounced to their
- originally intended recipient(s) (ala X-Envelope-To:) and the filter
- refined and/or the databases (described below) updated.
-
-2. My filter traps blank/non-existent To: lines as well as To: lines
- contained in From: lines, but firsts exempts the following categories
- from this check: mailing lists, local mail, mail originating in the
- country (e.g. in our case *.il) and mail coming from autosupport servers.
-
-Beyond implicit checks, it uses four DBM databases: two that exempt the
-message from any spam (beyond RBL) checks (software servers and strange mailing
-lists need to be here) -- one based on $sender_address and the other on
-$header_to: lines -- and, conversely, two databases for known spammers that
-have valid mail headers that aren't caught by implicit checks. All entries
-in these databases are lowercase so that we don't need two lines for
-'friend@public.com' and 'Friend@Public.com'.
-
-The sample filter package is at ftp://ftp.cs.huji.ac.il/pub/exim/spam_filter/
-
-Comments and suggestions are welcome.
git://git.exim.org / exim-website.git / blobdiff