ORF Enterprise Edition is an enterprise-level anti-spam solution that helps you to block spam before it reaches your network. It wedges into the SMTP conversations and monitors all incoming SMTP traffic. For the most effective filtering, ORF uses a combination of anti-spam technologies, such as DNSBL's, SURBL's or Greylisting to identify and blacklist unsolicitied emails. Custom tests are provided in addition to the above, e.g. regular expression-supported keyword filtering, attachment filtering or Active Directory-based recipient validation.