blacklisting and greylisting

  • install the postgrey package and add it to smtpd_recipient_restrictions

    • test sending emails using telnet (from your host maschine) or a MUA to your virtual email address


      this needs to be done without authentication

    • see how messages get blocked

    • try again in 10 min

    • send an email via your second mail server to an email account on your first system and watch the logs. Your mail server will try again until the mail is send to the intended mail account

    • Use either of postfix restart, postfix flush or postsuper -r QUEUEID to force resending

  • add some blacklists to your smtpd_recipient_restrictions

    • this can't be tested very well expect building your own blacklist server (beyond scope of current exercise)

    • Supply some common blacklist entries and pretend these will work.