[K12OSN] OT: just reduced spam by 95% with Free Software

[Les Mikesell]

Nils Breunese wrote:
> Terrell Prudé Jr. wrote:
> 
>> Nils Breunese wrote:
>>> Terrell Prudé Jr. wrote:
>>>
>>>> I will first admit that this is somewhat off-topic from K12LTSP.
>>>> That said, schools could benefit from this.  This is definitely
>>>> applicable for those of you who asked about using K12LTSP as an email
>>>> server for your students.
>>>>
>>>> We all know about the spam problem.  Well, over this last week, I
>>>> have been playing with OpenBSD's spamd as a possible solution.
>>>> Basically, I put the spamd box in front of my (yes, GNU/Linux) email
>>>> server.  I have now reduced the spam count in my inbox from close to
>>>> 200 a day down to...five.  FIVE.  This is without false positives.  I
>>>> have verified that by studying my spamd logs all week and comparing
>>>> them to my real email server's logs.
>>>>
>>>> For those of you with small pipes to the Internet, this is
>>>> *definitely* something you might want to consider.  It saves you some
>>>> bandwidth.
>>>>
>>>> If anyone's interested, let me know.
>>>
>>> If your K12LTSP server can handle it, why not just run spamd (which is
>>> just the SpamAssassin daemon, right?) on your K12LTSP server directly?
>>> I don't think there is a difference between OpenBSD's spamd and Fedora
>>> Core's spamd, is there?
>>
>> Good question.  Actually, there is a big difference, and a lot of people
>> confuse OpenBSD's spamd with that of SpamAssassin, since the name of the
>> executable happens to be the same.  They are in fact different programs
>> with different strategies of dealing with spam.  They are not
>> replacements for each other; rather, they are complements.
> 
> Ah, I found it [0]. Looks like 'just a collection of blacklists'. I'm 
> not sure I'd setup a separate box with another OS just for that 
> (different if you're familiar with OpenBSD), but yes, you might want to 
> offload the load that filtering spam takes to another box if your 
> K12LTSP needs all its power to serve your thin clients.
> 
> I don't have a K12LTSP server at the moment, but I use SpamAssassin with 
> dcc [1], pyzor [2] and razor [3] to fight spam on my servers (running 
> Plesk with qmail as MTA) which works nicely. You could add MAPS zones 
> (like spamhaus.org's zen.spamhaus.org, etc.) as blocklists or plug them 
> into SpamAssassin for extra scoring, but make sure you know which ones 
> you're using and why (they all have different policies and some include 
> others). Also, make sure to keep your list of zones up to date, because 
> a MAPS zone that no longer exists can delay your mail delivery pretty bad.
> 
> If you happen to run servers running Plesk check out 
> atomicrocketturtle.com's free Project Gamera [4] if you'd like to setup 
> a dedicated spam and virus filtering gateway.
> 
> Nils Breunese.
> 
> [0] http://www.openbsd.org/spamd/
> [1] http://www.rhyolite.com/anti-spam/dcc/
> [2] http://pyzor.sourceforge.net/
> [3] http://razor.sourceforge.net/
> [4] http://www.atomicrocketturtle.com/Joomla/content/view/77/29/
> 

I'd add MimeDefang to the list as perhaps the best:
http://www.mimedefang.org
It runs as a sendmail milter so you don't have to replace anything you 
already have or run a different OS, and lets you supply a small snippet 
of perl to control running your choice of virus and spam filters or any 
other operations you want.

-- 
   Les Mikesell
    lesmikesell at gmail.com