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Emails which have been retrieved from a POP server by SX-
GATE's mail client will be silently discarded if the mail server
refuses delivery due to the SPAM filter. There will be no
notification and it is not possible to undelete the email. The email
is lost irrecoverable!
To avoid loss of important emails you should be very carefully
when activating this option. You should select a value which
is rather to high than to low. Please note that automatically
deleting email may be subject to legal constraints or might even
be prohibited by law.
SPAM filter settings
In addition to the builtin rules database the SX-GATE SPAM filter can query several
Internet realtime lists. These have a notable impact on the detection ratio.
The settings on this screen apply to the global relay SPAM filter
as well as to the users' personal SPAM filter. The latter must be
enabled individually in the user administration of SX-GATE.
Do not activate these features when your internet connection
is a rather expensive dial-up link. Depending on the actual
configuration even an internal email might trigger an Internet
connection. Thus the dial-up link will be online frequently which
results in high expenses.
An other extremely useful extension is the Bayes filter. When enabled, the SPAM filter
keeps adapting to its environment by learning the typical vocabulary used in regular
emails and at the same time recognizing topics of current SPAM waves.
DNS based lists
Several blacklists are available in the Internet, which contain mail servers known to be
the origin of SPAM mails. Another form of blacklists contains web server addresses
that are advertised by SPAM mails (URI: URI Black Lists). Links in the message body
are checked against these URI Black Lists. Finally there are also whitelists with friendly
mail servers.
