[Mimedefang] MySQL/SA and mimedefang

Lucas Albers admin at cs.montana.edu
Thu Jul 3 18:26:01 EDT 2003


> On Thu, 3 Jul 2003, Mike Smith wrote:
>
>> Or would it be better to call spamassassin from say procmail and
>> have it do it on a per user basis via the -p flag? Seems kinda silly
>> to run SA again after mimedefang has already kicked it off.
>
Yes, who cares if SA is called twice.

The very easiest thing to do is thus.
Use 1 global spamassassin setting via mimedefang.
Then per user spamd called from procmail.

I originally planned to implement per user filtering in mimedefang
I started off with per user procmail spamd filtering, then planned to
implement per user in mimedefang.

I realized thusly:

Users dont' want to configure their filters.
Users don't configure their filters.
Most spam is obviously spam.
I don't want to muck around on something that is used for production.
I can use off the shelf software components....

Does it work well enough?
Yes.
I reject at 10 via mimedefang then tag at 5.0 via procmail.
The absolutelly wonderful thing is that I don't have to spend anytime on a
daily basis changing my filters, and users don't have to do anything.

My volume of spam has gone down to approximatelly 12% by percentage of
total messages, and .05% by volume.
This is a mail that is tagged as spam and yet still delivered.


Sample mail makeup:


Spam .05% by volume as measured by percentage of total size in megs.

Number of spams                     : 132 (11.96%)
Number of clean messages            : 972 (88.04%)
Total spam volume                   : 3491 kbytes
Total clean volume                  : 61 Mbytes


So for a breakdown of incoming mail by messages:

22.7%: 5947 messages accepted for delivery
77% 20199 messages rejected as spam before delivery.
100%: 26146 messages attempted delivery through my server.

Messages are rejected at a level with a false positive rate of
approximately 1/6000 and tagged at a false positive rate of 6/100.

For every valid mail message accepted, we reject approximately, 3.5 spam
mail messages.

--Luke
Computer Science MSU Bozeman,MT.



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