Re: New question about interaction between spamass-milter and clamav.

[EASY address@hidden]

On Tue, 2009-07-07 at 12:42 -0400, Steven W. Orr wrote:
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> I need some help with whether I'm doing something wrong.
> 
> Here's my setup:
> 
> I have
> sendmail-8.14.3
> spamass-milter-0.3.1-13 (set to reject)
> spamassassin-3.2.5
> 
> All was good in the world, but slowly the spam that got through was creeping 
> up.
> 
> I found that if I added clamav-milter that a lot of the stuff would get
> caught. I came to this list a while back to ask about the pros and cons of
> whether the clamav-milter should go before or after spamass-milter. I decided
> on doing clamav-milter first. Both milters were set to reject.
> 
> Then the false negs started climbing again and I heard about all the clamav
> addons that were available via scamp from
> 
> https://sourceforge.net/projects/scamp/
> 
> That made a huge difference and life was good again.
> 
> Again, things were escalating and I decided that the real problem is that
> every time clamav rejects something, spamassassin doesn't learn from it. The
> SA AWL and the bayes tables never get informed except for the false negs that
> get through that get fed to sa-learn --spam. I thought that it would make more
> sense for SA to run the clam test itself. I looked around and sure enough I
> found clamav.pm  which is a plugin for SA.
> 
> So where I am now is that I have eliminated the clamav-milter, and I'm running
> a clamd so that clamscam works, and I installed the clamav plugin to SA. The
> sendmail incantation I'm using is this standard one:
> 
> INPUT_MAIL_FILTER(`spamassassin',
>     `S=local:/var/run/spamass-milter/spamass-milter.sock, F=,
> T=C:15m;S:4m;R:4m;E:10m')dnl
> 
> and the params for running spamass-milter are
> 
>  -m -u steveo -r 5 -d misc -i 192.168.0.1/24 -i 127.0.0.1/24
> 
> I can't believe you've read this far. But if you got here then I can now ask
> my question:
> 
> Why is it that I am now seeing  my server asking for retries? I am getting
> rejects like I expect to get (and like I got before). For example,
> 
> Jul  5 05:17:17 saturn spamass-milter[3478]: queueid=n659HG7c007407
> Jul  5 05:17:18 saturn sendmail[7407]: n659HG7c007407:
> from=<address@hidden>, size=2174, class=0, nrcpts=1,
> msgid=<address@hidden>, proto=ESMTP, daemon=MTA,
> relay=sombody_good [good.guy.we.like]
> Jul  5 05:17:18 saturn sendmail[7407]: n659HG7c007407: Milter add: header:
> X-Virus-Scanned: ClamAV 0.94.2/9538/Fri Jul  3 10:27:11 2009 on
> myserver.syslang.net
> Jul  5 05:17:18 saturn sendmail[7407]: n659HG7c007407: Milter add: header:
> X-Virus-Status: Infected with Sanesecurity.Spam.10285.UNOFFICIAL
> Jul  5 05:17:19 saturn sendmail[7407]: n659HG7c007407: Milter: data,
> reject=554 5.7.1 virus Sanesecurity.Spam.10285.UNOFFICIAL detected by ClamAV -
> http://www.clamav.net
> Jul  5 05:17:19 saturn sendmail[7407]: n659HG7c007407:
> to=<address@hidden>, delay=00:00:01, pri=32174, stat=virus
> Sanesecurity.Spam.10285.UNOFFICIAL detected by ClamAV - http://www.clamav.net
> 
> 
> But now I'm also seeing retries when clamav is deciding that the status is
> unknown. Somehow, spamass-milter is returning a 4.5.1
> 
> Jul  5 04:55:56 saturn sendmail[19195]: n658tqMf019195:
> from=<address@hidden>, size=3879, class=0, nrcpts=1,
> msgid=<address@hidden>,
> proto=ESMTP, daemon=MTA, relay=201-94-178-5.jau.flash.tv.br [201.94.178.5]
> 
> Jul  5 04:55:56 saturn sendmail[19195]: n658tqMf019195: Milter add: header:
> X-Virus-Scanned: ClamAV 0.94.2/9538/Fri Jul  3 10:27:11 2009 on
> myserver.syslang.net
> 
> Jul  5 04:55:56 saturn sendmail[19195]: n658tqMf019195: Milter add: header:
> X-Virus-Status: Unknown
> 
> Jul  5 04:55:56 saturn sendmail[19195]: n658tqMf019195: Milter: data,
> reject=451 4.3.2 Please try again later
> 
> Jul  5 04:55:56 saturn sendmail[19195]: n658tqMf019195:
> to=<address@hidden>, delay=00:00:01, pri=33879, stat=Please try again later
> 
> I'm not sure that I have a complaint. It's just that I did not have any notion
> that spamass-milter had the ability to do anything but either accept or reject
> with a 500 series code and I wanted to understand what was going on. I figured
> that SA only returns an assessment, but it's spamass-milter that does the
> actual rejecting.
> 
> Can someone explain this? (And again, thanks for reading.)
> 
> 
> - --
> Time flies like the wind. Fruit flies like a banana. Stranger things have  .0.
> happened but none stranger than this. Does your driver's license say Organ ..0
> Donor?Black holes are where God divided by zero. Listen to me! We are all- 000
> individuals! What if this weren't a hypothetical question?
> steveo at syslang.net
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It makes sense to virus scan first and drop. In an ideal world you
should be taking out as much 'obvious' rubbish as early as you can in
the SMTP stage. Only give Spamassassin anything that other anti UCE
methods cannot latch on to.

Spamassassin takes some tweaking. I won't use the Bayes feature at all -
but that is a personal thing. You have to add rules that meet your
requirements and see the kind of trends you have.

Some examples of the false positives put up at : http://pastebin.com/
may get you some suggestions.