nethserver-mail-filter

Features

  • Anti-spam with DNSBL (see: nethserver-unbound)
  • Anti-virus
  • Attachment block
  • Real-time Blackhole List (RBL) (default disabled)
  • Sender Policy Framework (SPF) (default disabled)
  • Customized spam threshold
  • Sender WBL, Recipient whitelist

Configuration database

Postfix example:

postfix=service
  ...
  RblStatus=disabled
  RblServers=host1,host2..
  SpfStatus=disabled
  ContentInspectionType=amavisd-before-queue
  • ContentInspectionType {default,amavisd-before-queue}:
  • default, apply the default content inspection type, depending on what packages are installed. nethserver-mail-filter changes the default to amavisd-before-queue
  • amavisd-before-queue, executes anti-spam and anti-virus checks on open SMTP connections. Only CLEAN messages are allowed to enter the postfix queue

Amavis example:

amavisd=service
  ...
  SpamCheckStatus=enabled
  VirusCheckStatus=enabled

  AdminNotificationStatus=disabled
  AvailableDecoders=mail,asc,uue,hqx,ync,F,Z,gz,bz2,lzo,rpm,cpio,tar,deb,zip,7z,rar,arj,arc,zoo,lha,doc,cab,tnef,exe
  BlockAttachmentClassList=
  BlockAttachmentCustomList=pif
  BlockAttachmentCustomStatus=disabled
  BlockAttachmentStatus=enabled
  EnabledDecoders=mail,asc,uue,hqx,ync,F,Z,gz,bz2,lzo,rpm,cpio,tar,deb,zip,7z,rar,arj,arc,zoo,lha,doc,cab,tnef,exe
  RecipientWhiteList=
  SenderBlackList=
  SenderWhiteList=clienti@example.it,marketing@domain.com
  SpamDsnLevel=20
  SpamKillLevel=9
  SpamSubjectPrefixStatus=disabled
  SpamSubjectPrefixString=***SPAM***
  SpamTag2Level=5
  SpamTagLevel=2.0

RBL server list

Enable RBL checks, by adding zen.spamhaus.org to the RBL server list:

db configuration setprop postfix RblStatus enabled RblServers zen.spamhaus.org
signal-event nethserver-mail-filter-save