On SupportHost we use SpamAssassin to protect our customers’ email accounts from spam. SpamAssassin is active by default on all accounts and configured to reduce spam without generating false positives, which means that important emails do not end up in spam.
With our default settings all emails are checked. We have set a spam score of 5, a recommended average value that allows you to filter spam emails efficiently. The spam score is a number from 1 to 10, the lower the setting the more emails will be filtered, resulting in an increase in false positives. We have also set the filter so as not to eliminate spam mails, but to move them to a spam folder. This way, if there is a false positive, you can retrieve the email and move it manually to the inbox.
How to customize the filter
We give our customers the ability to customize the spam filter to configure it according to their needs, let’s see how. First of all you need to access the cPanel, scroll to the email section and click on “Spam Filters”.
Here we see various options, let’s see how to customize the filter in the most efficient way.
Setting the spam score
If you get too many spam emails the first step is to change the spam score. In the first section you see that the spam filter is active on all accounts and you can not deactivate it. By default this value is set to 5. By clicking on the link circled in red we can set it to 4 to block more emails.
Delete or move spam mails
As mentioned before, our default setting moves spam emails to a spam folder so that they can be found if there is a false positive. If you prefer you can change this setting and delete spam emails permanently. We recommend keeping them in a separate folder, so it’s bette if you don’t change these settings.
Scrolling down more we see another section where we can set up additional configurations.
In the first section we can add an email address or an entire domain to whitelist, meaning that all emails sent from that email address will never be considered as spam. If you want to add all the emails of a certain domain to whitelist you can use the format: *@domain.com
Don’t whitelist your email or domain, this would make it easier for spammers using your email address to send spam.
The blacklist works exactly as the whitelist, though with the opposite result. If you enter a domain or email address in blacklist this will always be blocked by the spam filter.
Customized spam score settings
This last tool is only for experienced users. It allows us to configure different parameters for the scores associated with emails. We recommend that you do not change any of these rules unless you have serious spam problems. If you make changes to this filter we recommend checking your spam folder for false positives.
If you want to alter some of these values we recommend the following changes:
- URIBL_DBL_SPAM: Set Score to 10 – This rule checks the text of the email searching for a domain included in Spamhaus Domain Block List
- URIBL_WS_SURBL: Set Score to 10 – This rule checks the text of the email searching for a domain included in Bill Stearns URI Blacklist
- URIBL_BLACK: Set Score to 10 – This list contains a list of domain names that are used by spammers