Software affected: SmarterMail V4.x
Description:
Recommended SPAM Settings for SmarterMail 4.x
Resolution:
We recommend the following settings for SmarterMail 4.x. Go
to Security > Anti-Spam Administration > Spam Checks tab. We also
recommend that when assigning weights to the various SPAM Checks that
you use increments of 10.
Declude Low Probability of Spam weight = 10
Medium Probability of Spam weight = 20
High Probability of Spam weight = 30
(Leave unchecked if you do not have Declude)
SPAMAssassin This is a single Thread Windows client that can handle approximately 25,000 emails per day. If your server processes more than this you may want to use SPAMAssassin in a standalone Linux configuration.
Bayesian Filter Weight = 10 (SPAM weight assigned to an email if it fails Bayesian filter test)
Max. Memory to allocate for filtering = 10MB
Message required for filter update = 500
SPF
Pass weight = 0 Senders IP is valid for senders domain
Fail weight = 30 Senders IP is not valid for senders domain
Soft Fail weight = 10 Senders IP is questionable for senders domain
Neutral weight = 0 No strong statement can be made for or against senders IP
PermError weight = 0 The SPF record could not be processed.
None weight = 0 SPF is not commonly adopted therefore, we suggest setting this to 0
Reverse DNS weight = 10
RBL: SpamCop weight = 10
RBL: SpamHaus SBL weight = 10
RBL: SpamHaus XBL weight = 10
Additional RBL’s can be added and weights applied.
To enable a SPAM
Check, click the check box associated with the various SPAM filtering
option you want applied to your incoming emails.
You can also enable “Blocking” of emails that fail individual SPAM checks. As
an example, enable Blocking for Reverse DNS, if an incoming email
message fails only the Reverse DNS test then, the message is assigned a
weight of 10, if the SMTP Blocking Weight Threshold is set to 10 then
the message is Blocked.
In order to adjust the weights of the various SPAM checks, click on the Edit link on the right of each SPAM Test item. You
can edit the values and then click Save to implement the changes or
clicking Cancel to close the Edit dialog without saving changes.
On the Filtering tab the default settings are shown below:
Low Probability of Spam weight = 10
Default Action: Prefix subject with text
Text to Add: SPAM-LOW
Medium Probability of Spam weight = 20
Default Action: Move to Junk E-Mail folder
Text to Add: SPAM-Medium
High Probability of Spam weight = 30
Default Action: Move to Junk E-Mail folder
Text to Add: SPAM-High
Once, you are
comfortable with your SPAM settings you may want to change the default
action on the High Probability from “Prefix subject with text” to
“Delete the Message”.
Enable Greylisting
: This feature bounces unrecognized incoming emails that are not included in either the Trusted Sender list or the White Lists.
If the incoming
message is received by an unknown sender the server will bounced the
initial message, when a valid email server retries sending the message
after the Block period (default 12 minutes) and within the Pass period
(default = 240 minutes) then the email is accepted. This creates a Record expiration for that email which is by default = 36 days. If another email is received from this same sender then this resets the Record expiration to 36 days.
If the messages is
received by someone in the Trusted Sender list or the White Lists then
the message bypasses Greylisting feature and is then processed by only
Anti-Virus Administration settings and then delivered.
Block Incoming and Outgoing SMTP connections
The idea behind SMTP
Blocking of Incoming and Outgoing email is to filter out Spam messages
before they are delivered to the Spool.
To enable Incoming and Outgoing SMTP Blocking,
log in as the System Administrator, go to Security, Anti-Spam
Administration, and Spam Check page.
Enabling Incoming SMTP Blocking can apply Spam filter checks such as SPF, Reverse DNS and RealTime Blacklist.
To configure Blocking
of Incoming SMTP connections, select the Spam checks you want applied
to Incoming email from the Spam Check page. Once, your selections are
made, click the SMPT Blocking tab. The Spam filtering checks that were selected on the Spam Checks page will be displayed under the Current Incoming Weights. In order to actually enable the Blocking feature, click the Spam Blocking Enabled Check Box. Next,
you can edit the Weight Threshold under Incoming Options, so that when
an email arrives and it exceeds the Weight Threshold value the email is
blocked and never delivered to the Spool.
For the SMTP Blocking of Outgoing email, Spam filter checks are applied to outgoing email prior to being put in the Spool. There
are additional Spam checks that can be selected such as: Declude,
SpamAssassin, Custom Headers, and the Bayesian Filters in addition to
those available for blocking of Incoming SMTP connections.
To configure the
blocking of Outgoing SMTP connections, select the Spam checks you want
applied to outgoing email from the Spam Checks page. Once, your
selections are made, click the SMPT Blocking tab. The Spam filtering checks that were selected on the Spam Checks page will then be displayed under the Current Outgoing Weights. In order to actually enable the Blocking feature, click the Spam Blocking Enabled Check Box. Next,
you can edit the Weight Threshold under the Outgoing Options, such that
when an outgoing email exceeds the Weight Threshold value the email is
blocked and never delivered to the Spool.
Then finally, click the Save
.
We recommend the following settings for SmarterMail 3.x. Go
to Security > Anti-Spam Administration > Spam Checks tab. We also
recommend that when assigning weights to the various SPAM Checks that
you use increments of 10.
Declude Low Probability of Spam weight = 10
Medium Probability of Spam weight = 20
High Probability of Spam weight = 30
(Leave unchecked if you do not have Declude)
Bayesian Filter Weight = 10 (SPAM weight assigned to an email if it fails Bayesian filter test)
Max. Memory to allocate for filtering = 10MB
Message required for filter update = 500
SPF
Pass weight = 0 Senders IP is valid for senders domain
Fail weight = 30 Senders IP is not valid for senders domain
Soft Fail weight = 10 Senders IP is questionable for senders domain
Neutral weight = 0 No strong statement can be made for or against senders IP
PermError weight = 0 The SPF record could not be processed.
None weight = 0 Many valid domains donot have SPF records, we suggest setting this to 0
Reverse DNS weight = 10
RBL: SpamCop weight = 10
RBL: SpamHaus SBL +XBL weight = 10
Additional RBL’s can be added and weights applied.
To enable a SPAM
Check, click the check box associated with the various SPAM filtering
option you want applied to your incoming emails.
You can also enable “Blocking” of emails that fail individual SPAM checks. As
an example, enable Blocking for Reverse DNS, if an incoming email
message fails only the Reverse DNS test then, the message is assigned a
weight of 10, if the SMTP Blocking Weight Threshold is set to 10 then
the message is Blocked.
In order to adjust the weights of the various SPAM checks, click on the Edit link on the right of each SPAM Test item. You
can edit the values and then click Save to implement the changes or
clicking Cancel to close the Edit dialog without saving changes.
On the Filtering tab the default settings are shown below:
Low Probability of Spam weight = 10
Default Action: Prefix subject with text
Text to Add: SPAM-LOW
Medium Probability of Spam weight = 20
Default Action: Move to Junk E-Mail folder
Text to Add: SPAM-Medium
High Probability of Spam weight = 30
Default Action: Move to Junk E-Mail folder
Text to Add: SPAM-High
Once, you are
comfortable with your SPAM settings you may want to change the default
action on the High Probability from “Prefix subject with text” to
“Delete the Message”.