| SpamWall Control Panel -
Tuning your SpamWall System |
The SpamWall system in it's default configuration
with it's multi-layer Spam Filtering Technology and
default set of Spam Scoring Levels is able to detect
and block or filter up to 98% of all Spam/UCE
received by the system.
The Spam Scanning & Filtering engine on the SpamWall
system also incorporates a number of "self-tuning"
and "auto-learning" mechanisms including Bayesian
Analysis and Learning, which are able to
automatically increase accuracy and sensitivity of
the system over time.
It is also possible to increase the percentage of
Spam/UCE detected and either blocked, quarantined or
tagged by modifying the "Spam Score Levels" in the
Spamfilter Config screen of the SpamWall control
panel.
Once you have been administering your SpamWall
system for a while and have a good overview of which
emails are processed, tagged and quarantined by the
system you will be able to determine the optimum
Spam Scoring Levels for your particular application.
By "tuning" the system over time you will be able to
achieve the optimum level of Spam/UCE detection and
management for your particular email user base and
the specific type and content of email messages
received by your users.
The default "Tag Level 1" refers to the minimum Spam
Score of an email message before it is tagged or "flagged" as being
possible Spam/UCE. Messages scoring over this level will cause the
system to the add "X-Spam-Status" and "X-Spam-Level" headers to the
email so that they can be identified on the recipient end if
necessary as being spam or not-spam and at what Spam Score Level the
message has been assessed at.
The default "Tag Level 2" will mark a message as Spam/UCE by
appending the "**SPAM**" tag to the message "Subject" line when it
scores 5 points or more. The "X-Spam-Status" tag is also changed
from "No" to "Yes" at this level.
The default "Action Level" is set at "15". This will cause the
SpamWall system to take the appropriate specified action on any
messages that score above this level. This action is usually to
either send the message to the Spam Quarantine mailbox on the
SpamWall system or otherwise forward them on to an offsite mailbox
(not on the SpamWall system) which you may have specified in the
"Spam Quarantine" screen of the SpamWall control panel.
Reducing these Spam Scoring default levels will detect more
Spam/UCE, but it may also potentially increase the number of "false
positives", this being legitimate email being blocked, quarantined
or tagged as Spam. In it's default configuration the SpamWall system
is designed to minimize false positives. With no additional
configuration or tuning the false positive rate is typically at less
than 0.1%, or less than one in every 10,000 email messages processed
by the system.
In addition to its low false positive rates, the SpamWall system can
be configured with a Spam Scoring "Action Level" which is high
enough that that even messages which are likely to be Spam/UCE are
not blocked or quarantined but rather marked with the "**SPAM**" tag
and "X-Spam-Status" and "X-Spam-Level" headers and forwarded on to
the intended recipient.
Once received these tagged messages can then either be checked
visually to see if there are any legitimate messages or otherwise
the user can set up their email client to detect and divert any
tagged messages to a "spam" or "junk" folder or mailbox.
In general, the Spam Scoring "Action Level", which is set at "15" by
default, should be kept reasonably high until you become familiar
with administering your SpamWall system as if this value is set too
low this may increase the possibility of a legitimate email message
being sent to the Spam Quarantine, in which case you may have to
retrieve it at the request of a user or otherwise check the Spam
Quarantine mailbox more carefully or more regularly to ensure that
there are no legitimate emails of any significance contained there.
The default Spam Scoring values set on the SpamWall system are quite
conservative so as to minimize the chance of any legitimate emails
being blocked or directed to the Spam Quarantine. It is recommend
that these levels be maintained until you become familiar with the
operation of your SpamWall and the type and content of the email
messages being processed by the system and are able to determine the
optimum levels for your particular application and email user base.
You can expect that over time you will adjust these default levels
downwards to an optimum level where a high level of Spam/UCE
detection and blocking is achieved with very little chance of any
legitimate email messages being blocked or quarantined.
A general example of the optimum Spam Scoring Levels for a SpamWall
system in a "production" environment would be as follows:
Tag Level 1: 2 to 3
Tag Level 2: 3.5 to 5
Action Level: 6 to 10
When setting the Spam Scoring Level values, the lower this number
the more sensitive the filter becomes.
The type and content of email messages is widely variable however in
general a Spam Score Level threshold of 3.0 to 3.5 should increase
the amount of Spam/UCE detected significantly but in most cases is
unlikely to produce a significant increase in the number of false
positives.
If you and your end users are receiving a significant number of Spam
emails being delivered to your email accounts you may decide to
adjust your Spam Scoring "tag" and "Action" levels to more sensitive
levels, such as in 3.5-5 range for the "Tag Level 2", and the "6-10"
level for the "Action Level" where messages scoring above this level
are directed to the Spam Quarantine.
If you are seeing only a relatively small number of Spam messages
you may decide to maintain your "Tag Level 2" at the current default
level of "5", or possibly even adjust this value higher, and your
"Action" level at the "15" default level or possibly higher. This
would depend on the needs and requirements of your particular email
user base and the specific type and content of email messages
received by your users, and your tolerance with respect to the
possibility of having legitimate email messages directed to the Spam
Quarantine.
Alternatively, if you are seeing a significant number of legitimate
emails being tagged as "SPAM" you may decide to reduce your filter's
sensitivity level by increasing the "Tag Level 2" level in the
Spamfilter Config screen of your SpamWall system. Likewise, if you
are seeing a significant number of legitimate emails being directed
the Spam Quarantine you may decide to reduce your filter's "Action
Level" sensitivity by increasing the Spam Scoring "Action Level"
value.
The default Spam Scoring Levels set on your SpamWall system are a
good overall default configuration for detecting and filtering
Spam/UCE and other unwanted email, and your SpamWall system will via
it's own auto-learning and auto-tuning mechanisms become more
sensitive and adept at the detection and handling of Spam/UCE and
other unwanted email over time. Based on your own requirements it
may still be a good idea for you experiment with and adjust the
sensitivity of your Spam Scoring Levels in order to achieve the best
overall level of Spam/UCE detection and management for your
particular email user base and the specific type and content of
email messages received by your users.
