ZyXEL Communications 5 Series - Manual (Page 293)

ZyWALL 5/35/70 Series User’s Guide
Chapter 15 Anti-Spam 293
The following table describes the labels in this screen.
Table 85 SECURITY > ANTI-SPAM > External DB
LABEL DESCRIPTION
External Database
Enable External
Database Enable the anti-spam external database feature to have the ZyWALL calculate
a digest of an e-mail and send it to an anti-spam external database.
The anti-spam external database sends a spam score for the e-mail back to
the ZyWALL.
Spam Threshold The anti-spam external database checks an e-mail’s digest and sends back a
score that rates how likely the e-mail is to be spam. The possible range for the
spam score is 0~100. The closer the score is to 100, the more likely the e-mail
is to be spam.
Set the spam threshold (from 0 to 100) for considering an e-mail to be spam.
The ZyWALL classifies any e-mail with a spam score greater than or equal to
the threshold as spam. It classifies any e-mail with a spam score less than the
threshold as not being spam.
A lower threshold catches more spam e-mails, but may also classify more
legitimate e-mail as spam.
A higher threshold lessens the chance of classifying legitimate e-mail as
spam, but may allow more spam to get through.
Action for No Spam
Score Use this field to configure what the ZyWALL does if it does not receive a valid
response from the anti-spam external database.
If the ZyWALL does not receive a response within seven seconds, it sends the
e-mail digest a second time. If the ZyWALL still does not receive a response
after another seven seconds, it takes the action that you configure here. The
ZyWALL also takes this action if it receives an invalid response.
Here are possible reasons that would cause the ZyWALL to take this action:
1. The ZyWALL was not able to connect to the anti-spam external database.
2. The ZyWALL connected to the anti-spam external database, but there was
no HTTP response within seven seconds.
3. The ZyWALL received an error code from the anti-spam external database.
4. The ZyWALL received an invalid spam score (for example a number higher
than 100).
5. The ZyWALL received an unknown response to the anti-spam query.
Tag for No Spam
Score Enter a message or label (up to 16 ASCII characters) to add to the mail
subject of e-mails that it forwards if a valid spam score was not received within
ten seconds.
Forward SMTP &
POP3 mail with tag in
mail subject Select this radio button to have the ZyWALL forward mail with the tag that you
define.
Discard SMTP mail.
Forward POP3 mail
with tag in mail subject Select this radio button to have the ZyWALL discard SMTP mail. The ZyWALL
will still forward POP3 mail with the tag that you define.