Antispam
Most home
users on cable or DSL connections run Windows. These computers can
be infected through viruses and worms to act as spam sewers sending
out mail. Current statistics show that most of the unwanted mail we
see today originate from these computers and not from open
relays which
were previously the prime target for sending out spam.
Greylisting
Greylisting
is based on the principle that unlike legitimate mail servers, virus-infected
computers sending out mail do not retry sending their
message if there is a delivery error on the first try.
Our appliances target Windows zombies by not accepting mail from them on the
first delivery attempt (greylist).