1. A method for reputation-based threat protection, the method comprising: maintaining one or more dictionaries for identifying sensitive data in memory, wherein the sensitive data is defined by policies of an identified organization; maintaining information in one or more databases concerning a plurality of identified threats; intercepting an e-mail message from a sender in the organization and addressed to a destination outside of the organization, wherein the e-mail message is intercepted prior to leaving a communication network of the organization; executing instructions stored in memory, wherein execution of the instructions by a processor: determines that the intercepted e-mail message includes sensitive data by searching for predefined patterns, wherein searching comprises reference to the one or more dictionaries stored in memory for identifying the sensitive data, identifies the e-mail message is a threat based on one or more reputation scores associated with the e-mail message and the determination that the e-mail message includes sensitive data, wherein the e-mail message is associated with the one or more reputation scores using the maintained information, and applies one or more enforcement actions based on the determination that the e-mail message includes sensitive data; and notifying the sender that the e-mail message was identified to be a threat.