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Jeremy Baker wrote:
<blockquote cite="mid:200709232058.55257.jab-76OBl6+JcyzDN57Tih+YPw@public.gmane.org" type="cite">
<pre wrap="">I use Maia Mailguard. It is an amavisd based web frontend that uses
spamassassin and clamav to process incoming mail. Works great.
</pre>
</blockquote>
The summary of all this is that generally most solutions use more than
one technique for finding spam. SpamAssassin performs pattern matching
in the email and meta data, greylisting and delayed banners check for
impatient MTAs, RBLs look for known spammers or for hosts that
shouldn't be sending email, OCR decodes images to look for words, razor
and pyzor compare messages with a network of MTAs, spam traps capture
spam and there are many more techniques.<br>
<br>
One thing that I've learned is that there isn't a fire-and-forget open
source solution. Each needs tuning and work to keep up. I tend to have
to re-tune my solution (MailScanner) quarterly. I use RulesDuJour to
keep spam assassin rules up to date daily, but I have to check for new
rule sets manually. MailScanner comes up with new ways to detect spam
so upgrading and reviewing it's changelog are valuable. Very rarely I
will institute a new MTA method (like delayed banner) or turn on a new
MailScanner feature.<br>
<br>
In my case my server processes about 10,000 messages a day. About 5,000
are refused before they submit the message. Of the 5,000 remaining
about 2,000 are spam.<br>
<div class="moz-signature">-- <br>
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<p class="jvoSig">Register for the <a href="http://onlinux.ca">Ontario
Linux Fest Conference</a> today!
<br>
A Linux Conference for users by users.</p>
--
<table class="jvoSig" border="0" cellpadding="1" cellspacing="0"
width="450">
<tbody>
<tr>
<td><b>John Van Ostrand</b></td>
<td align="right"><b>Net Direct Inc.</b></td>
<td> </td>
</tr>
<tr>
<td>CTO, co-CEO</td>
<td align="right">564 Weber St. N. Unit 12</td>
<td><a
href="http://maps.google.ca/maps?q=564+Weber+Street+North+Unit+12,+Waterloo,+ON+N2L+5C6,+Canada&ll=43.494599,-80.548222&spn=0.038450,0.073956&iwloc=A&hl=en">map</a></td>
</tr>
<tr>
<td> </td>
<td align="right">Waterloo, ON N2L 5C6</td>
<td> </td>
</tr>
<tr>
<td><a class="moz-txt-link-abbreviated" href="mailto:john-Da48MpWaEp0CzWx7n4ubxQ@public.gmane.org">john-Da48MpWaEp0CzWx7n4ubxQ@public.gmane.org</a></td>
<td align="right">Ph: 866-883-1172</td>
<td>ext.5102</td>
</tr>
<tr>
<td><b>Linux Solutions / IBM Hardware</b></td>
<td align="right">Fx: 519-883-8533</td>
<td> </td>
</tr>
</tbody>
</table>
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