Backscatter occurs when a spammer forges a return MAIL FROM address when sending out spam. For some unfortunate users, the forged address they use is that users real address. This can easily lead to hundreds if not thousands of "bounces" being returned to the poor unfortunate user whose email address was used as the MAIL FROM address.
Backscatter protection is automatic and built-in to Alligate. If the user receives more than 2 messages with a MAIL FROM: <> indicating a MTA generated bounce message within 10 minutes, Alligate will reject all of these types of messages until one has not been received for a 10 minute period.
These settings can be modified if desired by changing 2 registry entries.
HKEY_LOCAL_MACHINE\SOFTWARE\SolidOak\Alligate\Settings\Backscatter\BackscatterHitsReq = 2 (default)
The above entry sets the number of bounce messages received to invoke backscatter rejection.
HKEY_LOCAL_MACHINE\SOFTWARE\SolidOak\Alligate\Settings\Backscatter\BackscatterMins = 10 (default)
The above entry sets the time in minutes where if the BackscatterHitsReq criteria is met, to invoke backscatter rejection.
Basically, if the recipient receives BackscatterHitsReq or more messages in BackscatterMins the message will be rejected with a 550 Refused error.