InterScanTM Messaging Security Virtual Appliance - Online Help ...

Trend Micro InterScan Messaging Security Virtual Appliance Administrator’s Guide
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4. Select one of the following spam catch rates or specify a detection threshold.
• High: Catches more spam. Select a high catch rate if too much spam is getting
through to your clients.
• Medium: Catches an average amount of spam (the default selection).
• Low: Catches less spam. Select a low catch rate if IMSVA is tagging too many
legitimate email messages as spam.
• Specify a detection threshold: Specify a threshold value (between 3.0 and
10.0) that represents how critically IMSVA analyzes email messages to
determine if they are spam.
Note: A higher threshold value means that a message must be very "spam-like" for
IMSVA to consider it spam. This decreases the spam catch rate, but it also results
in a lower number of false positives. If IMSVA is tagging too many legitimate
email messages as spam (too many false positives), specify a higher threshold
value.
A lower threshold value means that a message only needs to be slightly
"spam-like" for IMSVA to consider it spam. This increases the spam catch rate,
but it also results in a higher number of false positives. If IMSVA is letting too
much spam through to your clients as legitimate email messages, specify a lower
threshold value.
5. Click DKIM approved list to enable or disable use of the DKIM Approved List.
IMSVA does not scan or mark messages as spam, if the messages come from
domains appearing in the DKIM approved list
6. Select the check boxes next to any of the following lists to enable them:
• Approved sender list: Prevents IMSVA from identifying email messages from
senders in this list as spam.
• Blocked sender list: Forces IMSVA to identify email messages from senders
in this list as spam.
• Text exemption list: Prevents IMSVA from identifying email messages that
contains any of the text in this list as spam.