Email Services Systems Administrator - TS/SCI with Polygraph

General Dynamics - IT; Annapolis (MD); On-site; USD 110,000 - 150,000; Full time

Job summary

General Dynamics - IT is seeking an Endpoint Management Systems Administrator to manage enterprise Exchange and M365 services across on-premises and cloud environments. You will ensure high availability, secure mail flow, and seamless migrations while supporting hybrid deployments for mission-critical operations.

Applicants should have TS/SCI clearance, DoD 8140 certification, and hands-on Exchange/M365 experience in complex multi-network settings.

Qualifications

• Hands-on experience administering Exchange (on-premises) and M365 messaging services in enterprise environments.
• Active TS/SCI clearance with a favorable polygraph.
• DoD 8140 Information Assurance Certification requirements (e.g., Security+ CE).

Responsibilities

• Administer, maintain, and troubleshoot Exchange and M365 with high availability across networks.
• Manage mailbox databases, transport services, journaling, archival/retention systems, SMTP relays, and message hygiene.
• Control identity and access, including PKI-based authentication and directory services integration.
• Monitor health, capacity, and performance; diagnose issues and implement fixes.
• Support migrations, upgrades, and sustainment of on-premises and cloud messaging platforms.

Skills

Exchange Admin

M365 Admin

Security Clearance TS/SCI

DoD 8140 Certification

Documentation

Education

Bachelor’s degree in IT-related field

Tools

PKI

Directory Services

Job description

ENDPOINT MANAGEMENT SYSTEMS ADMINISTRATOR

YOUR IMPACT

Own your opportunity to support national defense. Your work will help keep critical operations secure and connected across the global enterprise—directly, contributing to a mission that protects our nation every day.

CIO Infrastructure Services (CIS) is growing, and we invite both our experienced incumbents and new team members to be part of what’s next. Incumbents bring invaluable mission insight, while new talent adds fresh ideas and energy. Together, we’ll strengthen continuity and drive the next generation of innovation.

MEANINGFUL WORK AND PERSONAL IMPACT

As an Email Services Systems Administrator supporting CIS, you will operate, secure, and optimize enterprise email and messaging services across complex multinetwork environments. You will maintain high availability email platforms, ensure reliable communication services, and sustain cloud enabled collaboration capabilities that directly support mission critical operations. Your work enhances the resilience, performance, and readiness of enterprise messaging systems relied on by users worldwide.

KEY RESPONSIBILITIES

• Administer, maintain, and troubleshoot enterprise Exchange and M365 email systems, ensuring high availability, secure operations, and reliable mail flow across multiple networks
• Support email architecture components including mailbox databases, transport services, journaling, archival/retention systems, SMTP relays, and message hygiene tools
• Manage identity and access for messaging services, including authentication, PKI based access, mobile access policies, and integration with directory services
• Monitor system health, capacity, and performance; perform diagnostics; and implement corrective actions for service disruptions or degraded functionality
• Support migrations, upgrades, and sustainment of both on premise and cloud based messaging platforms, ensuring seamless integration and minimal user impact
• Execute backup, recovery, and failover operations for Exchange systems and related messaging components, validating resilience and continuity of operations
• Troubleshoot complex issues involving authentication, DNS, PKI, mobile clients, cross domain routing, and dependencies across hybrid environments
• Maintain documentation, SOPs, service configurations, and operational artifacts supporting sustainment, change management, and continuous improvement
• Apply security patches, cumulative updates, and platform hotfixes across Exchange, M365, and messaging related infrastructure to maintain compliance and secure service baselines
• Identify and remediate noncompliant messaging systems by reviewing vulnerability and SCAP reports, resolving patch exceptions, and validating corrective actions across messaging environments

WHAT YOU’LL NEED TO SUCCEED

• EXPERIENCE REQUIREMENTS:
  Email ServicesSystems Administrator Senior - Requires a Bachelor’s degree in an IT‑related field or 8+ years of relevant IT experience in lieu of a degree.
  Email ServicesSystems Administrator Principal - Requires a Bachelor’s degree in an IT‑related field or 10+ years of relevant IT experience in lieu of a degree.
  Email ServicesSystems Administrator Sr. Principal - Requires a Bachelor’s degree in an IT‑related field or 12+ years of relevant IT experience in lieu of a degree.
• CLEARANCE: Active TS/SCI clearance with a favorable Polygraph
• CERTIFICATIONS: Meet DoD 8140 Information Assurance Workforce certification requirements (e.g., Security+ CE)
• Hands-on experience administering Exchange (on-premises) and M365 messaging services in enterprise or multi-network environments
• Strong proficiency with email routing, SMTP, DNS, authentication, certificates, and mobile/ remote email access
• Experience with secure configuration, retention/archival policies, and compliance requirements for enterprise messaging
• Familiarity with patching, vulnerability remediation, and configuration compliance for messaging platforms
• Ability to diagnose and resolve complex messaging, access, routing, and authentication issues across hybrid environments
• Strong documentation, communication, and cross team collaboration skills
• US citizenship required

• LOCATION: Onsite

GDIT IS YOUR PLACE
At GDIT, the mission is our purpose, and our people are at the center of everything we do.
Growth: AI-powered career tool that identifies career steps and learning opportunities
Support: An internal mobility team focused on helping you achieve your career goals
Rewards: Comprehensive benefits and wellness packages, 401K with company match, and competitive pay and paid time off
Community: Award-winning culture of innovation and a military-friendly workplace
OWN YOUR OPPORTUNITY
Explore an enterprise IT career at GDIT and you’ll find endless opportunities to grow alongside colleagues who share your desire to drive operations forward.

#CIS