Exim (the server mail transfer agent) handles multiple small rules more efficiently than single large ones.
It is recommended to use multiple and simple email filters instead of creating a single large filter.
Login to your cPanel.
From the Email pane, click on Email Filter.
Select the email account to create a filter.
Click on "Manage Filters".
Click on "Create a New Filter".
Give the filter a name.
Select a rule from the existing Rules drop-down options.
The easiest and simplest rule you can create is to use Exim spam score.
To filter all mail that Apache SpamAssassin™ has marked with a spam score of 5.0 or greater, select the "Spam Bar" option.
On the right side of the rule option, select "contains".
The commonest (and probably the safest) Exim spam score is 5.
So type in "+++++" into the next field option.
If you wanted to match a spam score of 4, you would use ++++`.
For a spam score of 3, use +++
For "Actions", select deliver to the Junk folder.
This way, any email that has a spam score of above "5" is delivered to your Junk folder.
You can always access the folder to see if important emails are being marked as spam.
And then use Roundcube intelligent learning rule to whitelist the sending email address.
The Roundcube Junk and Not junk buttons in the upper-right section of the top menu bar train SpamAssassin™ to recognize spam and ham.
You can use the Empty Junk button (this appears above the messages in the Junk folder once you select that folder) to remove all the messages in the Junk folder at once.
Note that you can also achieve the same result by accessing the email account's Webmail interface directly and selecting "Email Filters" from the drop-down beside the email address.
