[CentOS] sendmail and spam

Ned Slider ned at unixmail.co.uk
Wed Jun 4 21:36:27 UTC 2008

Craig White wrote:
> On Wed, 2008-06-04 at 16:53 -0400, Alain Terriault wrote:
>> Hi,
>> What is todays most effective combination to filter spam ?
>> On my old Redhat 3 system I used Sendmail and Spamassasin .. it was
>> good, but with the current setup we are getting way to much spam.
>> Looking around I found new players, well some I did not know then and
>> they are very interesting..
>> MailScanner .. http://www.mailscanner.info/
>> Sagator .. http://www.salstar.sk/sagator/
>> Smf .. http://smfs.sourceforge.net/index.html
>> dspam .. http://dspam.nuclearelephant.com/index.shtml
>> I am tempted to go with smfs because it is familiar .. but, mailscanner
>> seems popular
> ----
> I use MailScanner but it still uses spamassassin.
> I use postfix and greylisting and block e-mails that coming from hosts
> that don't resolve by reverse dns or for that matter don't have valid
> hostnames. I also use some rbl's.
> Those things alone and greylisting knock down most of it so spamassassin
> has a much lighter load and MailScanner is awesome.

Same here - I use a 3 phase approach to pre-filtering spam. I use 
postfix restrictions (requiring a FQDN helo hostname blocks ~30% on my 
server), DNSBL's (zen.spamhaus.org, dnsbl-1.uceprotect.net, 
psbl.surriel.com, bl.spamcop.net) and greylisting which in combination 
blocks >99% of all spam _before_ it enters the server and needs any 
costly post-filtering by SpamAssassin/ClamAV etc. It's an extremely 
effective solution for me (YMMV).


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