Please note for Fedora and EPEL 7+ we use only systemd.
upstart and sysvinit only apply to EPEL 6.

A clamav-milter setup consists of the following three components:

* the clamav-milter itself

  --> this is provided by the 'clamav-milter' package plus (alternatively)
      'clamav-milter-upstart' or 'clamav-milter-sysvinit'

  The main configuration is in /etc/mail/clamav-milter.conf and MUST
  be changed before first use.

  This can be enabled with: 'systemctl enable clamav-milter.service'

  The -sysvinit package is managed by the traditional tools, but
  -upstart requires modification of /etc/event.d/clamav-milter to
  enable automatic startup.  See comments there for more details.

* a clamav scanner daemon

  --> this is in the clamd package (or on EL6:
      'clamav-scanner-upstart' or 'clamav-scanner-sysvinit')

  The daemon is configured by /etc/clamd.d/scan.conf (which MUST be
  edited before first use).

  This can be enabled with: 'systemctl enable clamd@scan.service'

  The -sysvinit package is managed by the traditional tools, but
  -upstart requires modification of /etc/event.d/clamd.scan to enable
  automatic startup.  See comments there for more details.

* the MTA (sendmail/postfix)

  --> you should know how to install this...

  When communicating across unix sockets with the clamav-milter, it is
  suggested to use the /run/clamav-milter/clamav-milter.socket
  path.  You have to add something like

    INPUT_MAIL_FILTER(`clamav', `S=local:/run/clamav-milter/clamav-milter.socket, F=, T=S:4m;R:4m')dnl

  to your sendmail.mc.


EXAMPLE
=======

For clamav-milter, a possible setup might be created by

A)  On the MTA  (assumed hostname 'host-mta')

  1. Add to sendmail.mc

    | INPUT_MAIL_FILTER(`clamav', `S=inet:6666@host-milter, F=, T=S:4m;R:4m')dnl

  2. Rebuild sendmail.cf


B)  On the clamav-milter host (assumed hostname 'host-milter')

  1. Install clamav-milter + clamav-milter-upstart packages

  2. Set in /etc/mail/clamav-milter.conf

    | MilterSocket	inet:6666
    | ClamdSocket	tcp:host-scanner:6665

     and all the other options which are required on your system

  3. Enable clamav-milter.service:

    | systemctl enable clamav-milter.service

     Restart your system or execute

    | systemctl start clamav-milter.service

  4. Add something like

    | iptables -N IN-cmilt
    | iptables -A IN-cmilt -s host-mta -j ACCEPT
    | iptables -A IN-cmilt -j DROP

    | iptables -A INPUT -p tcp --dport 6666 -j IN-cmilt

     to your firewall setup

C)  On the clamav-scanner host (assumed hostname 'host-scanner')

  1. Install clamd

  2. Add to /etc/clamd.d/scan.conf

    | TCPSocket 6665
    | TCPAddr   host-scanner

     comment out possible 'LocalSocket' lines and set all the other
     options which are required on your system

  3. Enable clamd@scan.service:

    | systemctl enable clamd@scan.service

     Restart your system or execute

    | systemctl start clamd@scan.service

  4. Add something like

    | iptables -N IN-cscan
    | iptables -A IN-cscan -s host-milter -j ACCEPT
    | iptables -A IN-cscan -j DROP

    | iptables -A INPUT -p tcp --dport 6665 -j IN-csan

     to your firewall setup