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.

ORF's most effective spam filtering feature is the ability to use multiple external spam source databases (DNS blacklists) simultaneously. ORF is shipped with a predefined set of DNS blacklist definitions and the list can be extended. Most of these DNS blacklists are updated almost every second which guarantees that ORF can block even the most up-to-date spam attacks. For the most effective filtering ORF also offers custom tests in addition to the DNS blacklists usage, such as regular expression-supported keyword filtering and attachment filtering or Active Directory-based recipient validation.

You can also create your own IP address, sender and recipient email address lists. While the whitelists can be used to exclude hosts, senders or local mailboxes from filtering, the same type of blacklists help you reject messages from specific hosts or IP ranges, senders (domains) or local mailboxes.

ORF can be used with Windows 2000/2003 built-in IIS SMTP Service and Microsoft Exchange 2000/2003 Servers (which use this service for SMTP communication).

ORF was designed with high-performance and robustness in mind, it performs well even under heavy usage. It is being used in networks with a daily average of 2-3 millions incoming email without any performance problems.