Spam has become a major issue over the last few years. In order to help combat the spread of spam, we use SpamAssassin on all our mail servers. SpamAssassin uses a technology called spam tagging. Spam tagging uses an extensive list of rules and values that rate messages to determine whether or not the message is spam. SpamAssassin, does nothing else but determine whether the message is considered spam or not. It is up to you to decide what to do with the message once it is marked as spam. You have the option to delete the message, tag the header of the mesage, or send the message to the SpamCatcher. We go into more detail about these options below. In order for SpamAssassin to work, the spam filter must be enabled on each individual email address through your NetAdmin with the following steps:

• 1) Click on Manage Email Accounts
  
• 2) Click Modify next to an email address
  
• 3) Click the Spam Filter link
  
• 4) Select the Enabled option
  

  Here is where you decide what you want to do with the message once it has been marked as spam. You will need to select one of the following options:

  • Send to SpamCatcher - You can login to SpamCatcher by visting mail.your_domain.com/spamcatcher. You will use your email address and password to login and view the messages that have been caught by the spam filter. If there is a message that isn't spam in the SpamCatcher, you can mark the message(s) as not spam, by selecting the message and clicking the Not Spam button. This will send the message back to the server so you can download it to your webmail and/or client. However, by marking the message as not spam, this doesn't mean that all future messages like this will be tagged as not spam. The Not Spam, button will only mark that single message as not spam. You will need to configure your spam filter in order to allow messages from this domain and/or sender to be marked as not spam in the future.
    
  • Tag Headers - Messages determined to be spam will be tagged with your custom subject so you can filter the email messages with your own email client. Example: If your subject tag in the spam filter is "SPAM", and you select the Tag Headers option, SpamAssassin will add the word "SPAM" to the subject line of all messages that are marked as spam, and deliver them normally to your e-mail client for your to filter yourself. If you add nothing to the subject tag field, but select Tag Headers, spam will be delivered with asterisks in the subject.
    
  • Delete Message - This will simply delete any messages deemed to be spam. This is not recommended because although SpamAssassin is very effective at marking spam, sometimes it does mark messages that aren't spam "false positives". It is best to tag the header, or send the spam to the SpamCatcher before you delete it.
    
    
• 5) Click Save
  

You will need to do this for each of your email addresses on which you want to filter spam. Keep in mind that if you are having the messages forwarded to another email account, the spam filter does not filter messages that are forwarded.

Once you have the spam filter enabled on one or more email addresses you can edit the spam filter master configuration to setup specific options, like black lists, white lists, etc. To get to it you can click on the Spam Filter link under the heading Feature Management in your NetAdmin.

On the spam configuration page you will see several items:

• Required Score - Each message that is sent to you is assigned a spam score based on things like the subject, from address, message content, etc. The required score designates how high of a spam score is too high, by default it is set to 5. This means that any messages with a spam score higher than 5 will be blocked as spam. The lower you set this score the more messages will be caught in the spam filter. If you set this score too low you will start to get a lot of "false positives", or messages that are not spam, but get caught in the filter.

• Subject Tag - Any message that is tagged as spam will have whatever you type in this box appended to their subject line. This is useful if you want to filter the spam yourself in your own email client, otherwise its best to just leave it blank.

• Use Bayes Filters - This is the auto-learn feature of the spam filter. If this is turned on you can send spam messages you receive to spam-your_email_address@your_domain.com and this will help train the spam filter to better identify spam

• WhiteList_Auth - You should enter your domain name(s) or email address(es) to the WhiteList_Auth list. More coming soon.

• WhiteList_From - You can enter domain names and email addresses in this box that you want to have white listed in your spam filter. A white list is a list of domains and/or specific users that SpamAssassin will ignore and never tag any messages from this sender as spam. (You should NEVER add your local domain name or email address to the WhiteList_From list as this will allow spam to be delivered to your accounts.) You add them in the format:
  address@domain.com (to allow all email from a single address)
  *@domain.com (to allow all email from an entire domain)

• BlackList_From - You can enter domain names and email addresses in this box that you want to have black listed in your spam filter. A black list is basically the opposite of a white list. SpamAssassin will tag all messages sent from any domains and/or users added to the blacklist as spam. You add them in the format:
  address@domain.com (to block all email from a single address)
  *@domain.com (to block all email from an entire domain)

• Custom Configuration Entries - In this box you can enter SpamAssassin custom commands to customize the spam filter further. If you enter "help" in this box and then click save it will return a list of valid commands. You can find a list of what each entry means, and performs by visiting the SpamAssassin website here. These commands may be considered advanced to the casual user and in most cases are not necessary.

Spam Filter FAQ:

• Why are messages sent from users on my domain to users on my domain caught in the spam filter?
  The spam filter looks at many aspects of the email message, not just the sending address so valid email messages can be labeled as spam. You can add the following entry to your custom configuration to resolve this issue: whitelist_auth *@your_domain.com

• After I enable SpamCatcher for an e-mail account and refresh the page, the SpamCatcher for that account will default back to .disabled.. I am also forwarding e-mails from this account to other accounts. Why can't I enable SpamCatcher?
  You don't have the ability to configure your spam filter to filter e-mails before they are forwarded. If you are forwarding e-mails with this account, and are trying to enable the spam filter but can't, you will need to contact support for assistance in configuring your spam filter to do this. If you aren't forwarding e-mails from this account, but are still experiencing this issue, please try clearing your browsers cache and cookies or try using a different browser.

• There are particular spam e-mails that continue to make it through to my inbox. Is there anyway I can add these to the spam filter?
  Make sure that the Use Bayes Filter option in the spam filter is set to "yes". By doing this, you can then forward spam that is getting through to spam-youremail@yourdomain.com. Doing this will help train the spam filter to identify that type of message as spam in the future. This will train the spam filter for every e-mail account that uses your domain, not just the one you are forwarding the spam to.