Outbreak Filters can take the action of rewriting URLs to redirect traffic to potentially harmful websites through a web security proxy. This allows the Cisco Secure Email Gateway to scan the content of the websites and block or warn the user if they are malicious or undesirable. This action can stop small-scale and nonviral attacks, such as phishing scams and malware distribution sites, that may not be detected by other filters. References: [Cisco Secure Email Gateway Administrator Guide - Configuring Outbreak Filters]