Smarter Mail Recommended SPAM Settings by Cloud Techtiq

    Posted in Smarter Mail on Nov 23, 2018

    it’s important to remember that spam administration is not a "fire and forget" task. Using these built-in options requires constant tweaking to keep that level of effectiveness, and mail administrators will need to monitor incoming and outgoing spam as spammers frequently change their tactics.

    SmarterMail comes equipped with several industry-standard antispam options that can block up to 97% of all spam from entering or leaving the server and help keep mail systems running smoothly, including SPF, reverse DNS, greylisting and more. And this is done by the Message Sniffer and Cyren Premium Antispam services. Using one of these services, or ideally both together, is easily the most effective option in battling spam.

    First of all Follow these steps to review your spam settings:

    1. Log into SmarterMail as a System Administrator.

    2. Click on the Settings area.

    3. In the navigation pane, click on Antispam.

    Below are some recommendations for the various spam settings SmarterMail has to offer:-

    1. SPAM CHECKS

    Each spam check comes with unique spams weights, which can be adjusted as desired. In the Spam Checks, RBL Lists and URIBL Lists sections, you can enable individual spam checks for email spool filtering and incoming/outgoing SMTP blocking.

    Determining the weight values of each spam check depends on how accurately you believe that check identifies spam messages. Find our recommended spam weight values below:

    Cyren Premium Antispam

    (Leave disabled if you do not have the Cyren add-on)

    Low Probability of Spam weight = 10

    Medium Probability of Spam weight = 20

    High Probability of Spam weight = 30

    Message Sniffer

    (Leave disabled if you do not have the Message Sniffer add-on) Confirmed Weight = 30 None Weight = 0

    Remote SpamAssassin

    SpamAssassin itself is a powerful, third party open source mail filter used to identify spam that can be easily used alongside, or in place of, SmarterMail’s spam settings. It utilizes a wide array of tools to identify and report spam.

    DKIM

    (DKIM is the primary mechanism for signing messages which proves to the receiving user that the message was not altered during transit and was sent from the signing domain. Not all valid messages are signed however so no spam weight should be given for no signature.)

    Pass Weight = -5

    Fail Weight = 5

    None Weight = 0

    SPF

    Pass weight = 0 (Sender’s IP is valid for sender’s domain)

    Fail weight = 30 (Sender’s IP is not valid for sender’s domain)

    Soft Fail weight = 10 (Sender’s IP is questionable for sender’s domain)

    Neutral weight = 0 (No strong statement can be made for or against sender’s 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

    2. FILTERING

    On the Filtering card within the Options tab, you can adjust the global actions taken on emails that are considered to be spam, based on one of three probabilities determined by their spam weights. The defaults for Filtering are as follows:

    Low Probability

    Spam weight = 10

    Default Action: Prefix subject with text

    Text to Add: SPAM-LOW

    Medium Probability

    Spam weight = 20

    Default Action: Move to Junk E-Mail folder

    Text to Add: SPAM-MEDIUM

    High Probability

    Spam weight = 30

    Default Action: Move to Junk E-Mail folder

    Text to Add: SPAM-HIGH

    3. SMTP BLOCKING

    On the SMTP Blocking card within the Options tab, you can access the configuration options for SMTP Blocking. The idea behind SMTP blocking of incoming and outgoing email is to filter out spam messages before they are delivered.

    For example, imagine you have four spam checks enabled for Incoming SMTP Blocking and each of those spam checks have a weight of 10. If the Incoming Weight Threshold is set to 30, that means messages being received via SMTP will be rejected if they fail three or all four of the spam checks. (Because SMTP blocks are done at the IP level and not based on message content, some spam checks do not offer incoming or outgoing SMTP blocking.)

    4.GREYLISTING

    On the Greylisting Options card within the Options tab, you can enable greylisting. Greylisting is a popular method of fighting spam as it temporarily rejects unrecognized incoming emails that are not sent by whitelisted or authenticated users, effectively saying, “Try again later.” Valid servers will retry the email a short time later, which would be permitted and delivered. Spammers, on the other hand, rarely retry on temporary failures, therefore reducing the amount of spam that customers receive. Find our recommended values below:

    Block Period = 3 minutes

    Pass Period = 360 minutes (6 hours)

    Record Expiration = 36 days