Sendmail

One modification to sendmail.mc:

    INPUT_MAIL_FILTER(
        `mimedefang',
        `S=unix:/var/spool/MIMEDefang/mimedefang.sock,
            F=T,
            T=C:5m;S:2m;R:2m;E:5m'
    )

Needs libmilter:

libmilter-dev package on Debian GNU/Linux
Simple compile time option for sendmail