ESET MAIL SECURITY 4 - FOR MICROSOFT EXCHANGE SERVER FOR WINDOWS SERVER 2000-2003-2008 User Manual page 10

the message scores 100 and no other checks are
made.
The Allowed IP addresses tab lists all IP addresses
that are approved, i.e., if the first non-ignored IP in
Received headers matches any address on this list,
the message scores 0 and no other checks are
made.
The Ignored IP addresses tab lists addresses that
should be ignored during Real-time Blackhole List
(RBL) checks. The list should include all internal IP
addresses in the firewall not directly accessible from
the Internet. Doing so prevents unnecessary
checks and helps to differentiate the external
connecting IP addresses from the internal IP
addresses.
section Message quarantine in the Advanced settings
window.
Performance
If there are no other restrictions, our recommendation is
to increase the number of ThreatSense scan engines
according to this formula: number of scan engines = number
of scan threads and increase the number of VSAPI
scanning threads based on this formula: number of scan
threads = (number of physical CPUs * 2) + 1 in the Advanced
settings window under Antivirus and antispyware >
Performance.
NOTE: We recommend that you set the number of
ThreatSense scan engines equal to the number of scan
threads used.