Functions as the engineer for Email & Messaging platforms, with primary accountability for Microsoft Exchange, Microsoft Exchange Online, Exchange Online Protection / Microsoft Defender for Office 365, Cisco Secure Email (IronPort/ESA or CES), secure SMTP relay, and hybrid Exchange services. The ideal candidate is a hands-on engineer with excellent communication skills who can design, secure, operate, and continuously improve enterprise mail flow at global scale. This role resolves complex messaging issues, designs and implements security and authentication controls (SPF/DKIM/DMARC), and partners closely with Information Security and Identity teams to protect users against phishing, BEC, malware, and data loss. The engineer contributes to research, analysis, design, implementation, and sustainment of resilient, auditable, and compliant messaging services that meet current and future business and security requirements.