Yes definitely Brightmail can do that. A content compliance policy is a set of simple and complex conditions and actions that determine how email message content and attributes are evaluated and how the email is handled as a result of that evaluation.
You can configure compliance policies to filter content:
- Block email from marketing lists that generate user complaints or use up excessive bandwidth.
- Block or redirect messages or attachments with specific content or specific file attachment types or filenames.
- Control message volume and preserve disk space by filtering out oversized messages.
- Prevent confidential or sensitive information from being sent to competitors.
- Limit ability of email users to communicate language or conduct activities contrary to your organization's values and policies.
Reference:
http://seer.entsupport.symantec.com/docs/322195.htm