Sr. Exchange Online (EXO) Administrator (Systems Engineer)

  • System One
  • Washington, Washington DC
  • 10/23/2026
Full time Information Technology Telecommunications

Job Description

Job Description Job Description

Senior Exchange Online (EXO) AdministratorWashington, DC -100% onsitePer Federal contract U.S. citizenship is requiredMust be able to obtain Public Trust clearanceStart Date- 08/2026 through 12/2027 with possibility of long-term contract extension based on performanceOpen to W2 and C2CMust apply by June 30th Position Summary Manage and maintain our hybrid Exchange environment, including on-premises Exchange Server and Exchange Online (Microsoft 365). Ensure reliable email services, security, and compliance across the organization.Key Responsibilities • Administer and support hybrid Exchange infrastructure (on-premises and Exchange Online) • Manage mailbox migrations, mail flow, and hybrid connectivity between environments • Configure and maintain transport rules, DLP policies, retention policies, and email security features • Monitor system performance, troubleshoot issues, and resolve user email problems • Implement anti-spam, anti-malware, and threat protection using Microsoft Defender for Office 365 • Manage user provisioning, distribution groups, shared mailboxes, and permissions • Maintain hybrid synchronization and directory services (Azure AD Connect) • Execute eDiscovery, legal holds, and compliance investigations • Document configurations, procedures, and maintain system architecture records • Provide end-user support and training on email featuresRequired Technologies • Microsoft Exchange Online & Exchange Server (hybrid environment) • PowerShell (Exchange Online/On-Prem Management) • Microsoft 365 Admin Center & Exchange Admin Center (EAC) • Azure Active Directory & Azure AD Connect • Exchange Online Protection (EOP) & Microsoft Defender for Office 365 • DNS, SPF, DKIM, DMARC, mail flow routingRequired Experience • 4+ years managing Exchange environments • 2+ years with hybrid Exchange (on-premises + Exchange Online) • 2+ years PowerShell scripting for Exchange administration • Hands-on experience with mailbox migrations and hybrid deployments • Email security and compliance implementationPreferred Qualifications • Microsoft 365 Certified: Messaging Administrator Associate • Experience with 500+ user environments • ITIL or service management experience

Ref: