To create the rule:

1. Log on to the Worry-Business Security console.
2. On the Messaging Security Agent configuration, click Content Filtering.
3. Click Add > Filter messages that match any condition defined > Next.
4. Type a rule name and select the Subject checkbox.
5. Click Next.
6. Select Any specified keywords from the Match field.
7. In the Enter keyword(s) field, type "REG. ^[\s]*$".
    

   Do not include the quotation marks.

    
8. Unselect the Match case-sensitive and Match-synonyms options.
9. Click Next.
10. Select the action to be taken on messages that match the new content filter rule.
11. Under People to Notify section, configure the settings you prefer.
12. Click Finish.
13. Check the Enable content filtering option.
14. Under the Enable section, check if the rules you want to be active have green icon. If the icon is red, click on it and it will turn green.