The Trend Micro Anti-Spam engine (TMASE) provides spam filtering of incoming messages.
Incoming messages refer to those messages sent by SMTP protocol. Spam filtering allows
ScanMail to block unwanted messages based on the following components:
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Order
|
Component
|
Source
|
Description
|
|
1
|
Approved Senders
|
User-defined
|
A list of people and/or organizations from whom messages will be accepted.
Other messages take the Action on unwanted messages.
|
|
2
|
Blocked Senders
|
User-defined
|
A list of people and/or organizations from whom messages will be blocked.
Other messages will be accepted.
|
|
3
|
Rule files
|
Trend Micro
|
Consist of heuristic and URL signature files. The Trend Micro Anti-Spam engine uses
these files to filter for spam messages when there are no approved and blocked senders
defined.
|
 |
NoteIf there are no approved senders or blocked senders set, TMASE will use the Trend
Micro rule files.
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TMASE provides three filter levels. The following table shows an example of when and
how TMASE tags messages as spam:
|
Filter Level/Sensitivity
|
Threshold Level
|
|
High (Rigorous filtering)
|
4.0
|
|
Medium (Default filtering)
|
5.0
|
|
Low (Lenient filtering)
|
8.0
|
where:
-
Filter level defines the TMASE sensitivity when filtering for spam
-
Threshold level defines the maximum allowable spam scoreIf the total spam score is equal or greater than the threshold level, then TMASE tags a message as spam. Otherwise, if the total spam score is less than the threshold level, ScanMail proceeds to the next filter execution order (see Filter Execution Order).
|
NoteSMD5.0 and above has a dynamic threshold level, which changes according to different
spam rules.
|
For example:
In this example, the filter level is set to Medium. The highlighted items refer to
the spam scores. The first spam score, 15.20, is greater than the threshold level
(that is, 5). This instructs TMASE to tag the message as spam. On the other hand,
the second spam score, 3.726, is less than the threshold level. This prevents TMASE
from tagging the message as spam.
To configure the filter level or Approved and Blocked Senders lists, see Configure Anti-Spam Filtering.