http://howtoforge.com/howtos/email/antispam-antivirus
drugače pa še jaz nimam neke potrebe po čem takem, samo v postfix confu sem dodal da preverja nekatere stvari
smtpd_helo_required, disable_vrfy_command, strict_rfc821_envelopes, invalid_hostname_reject_code, multi_recipient_bounce_reject_code ...
smtpd_recipient_restrictions =
reject_invalid_hostname,
reject_unknown_recipient_domain,
reject_unauth_pipelining,
permit_mynetworks,
permit_sasl_authenticated,
reject_unauth_destination,
reject_rbl_client multi.uribl.com,
...
reject_rbl_client rabl.nuclearelephant.com,
permit
etc ... antispam softwera pa nimam spljoh, pa dela super :D .