This presentation provides practical guidance for State, Local, Tribal, and Territorial (SLTT) organizations considering DMARC (Domain-based Message Authentication, Reporting & Conformance) implementation to enhance their email security posture. Drawing from cross-sector implementation experiences, we will outline a framework for DMARC adoption that addresses common challenges faced by government entities. Topics include conducting preliminary infrastructure assessment, developing appropriate DMARC policies aligned with federal guidelines, and establishing monitoring protocols. The discussion will highlight critical decision points in the implementation journey, resource allocation strategies, and methods for measuring success. Special attention will be given to common pitfalls and their solutions, interdepartmental coordination requirements, and strategies for maintaining constituent services during deployment. This presentation aims to equip SLTT organizations with actionable insights for successful DMARC implementation while ensuring compliance with relevant security standards and maintaining operational continuity. DMARC (Discovery) • Create a comprehensive inventory of your email domain landscape - Map all domains and subdomains - Identify all authorized email senders (internal and external) - Document current authentication methods (SPF/DKIM) • Key Point: You can't protect what you don't know about Get Set (Strategy) • Prepare your organization and infrastructure: - Develop monitoring capabilities before changing any policies - Establish baseline metrics for normal email patterns - Create clear roles and responsibilities - Build relationships with key stakeholders and vendors • Key Point: Proper preparation prevents poor performance GO! (Implementation) • Execute your plan with controlled, measured steps: - Begin with monitoring mode (p=none) to gather data - Move to quarantine for increasingly larger segments - Progress to reject policy based on data-driven decisions - Monitor, adjust, and communicate throughout • Key Point: Success is a journey, not a race