Microsoft 365 Security Administrator

System One; Atlanta (GA); On-site; USD 85,000 - 110,000; Full time

Job summary

System One, Inc. is seeking a Microsoft Systems Administrator (Microsoft 365 Security Administrator) to support, maintain, and secure Microsoft 365 environments.

The role focuses on O365 administration, email security, and access controls. You will configure conditional access, manage Intune, monitor Defender alerts, support Purview policies, and collaborate with internal teams and vendors to ensure secure services.

Qualifications

• Experience administering Microsoft 365 environments.
• Hands-on with Intune, Defender, Purview, Entra ID (Azure AD), Exchange Online and email security.
• Experience in regulated environments and knowledge of NIST or similar frameworks.
• Microsoft certifications such as M365 Administrator, Endpoint Administrator or Azure Administrator.

Responsibilities

• Configure and maintain Conditional Access Policies, MFA and access controls.
• Administer Intune for endpoint management, device compliance and deployments.
• Monitor Defender alerts and respond to security incidents.
• Support Purview policies including data protection, retention and compliance.
• Manage email security, threats, and vulnerabilities remediation.
• Support Windows endpoints and Windows Server administration.
• Perform system monitoring, patching and vulnerability remediation.
• Maintain documentation and support IT projects and initiatives.
• Collaborate with internal teams and vendors for secure services.

Skills

Microsoft 365

Intune

Defender

Purview

Entra ID/Azure AD

Exchange Online

IAM / Identity and Access

NIST compliance

Windows Server

Mimecast

Public sector experience

Tools

Mimecast

Azure

Windows Server

Job description

We are seeking a Microsoft Systems Administrator ( Microsoft 365 Security Administrator ) to support, maintain, and secure Microsoft 365 environments. This role will administer Microsoft O365 and email security services, manage user and device access, endpoint management, and maintain security controls across the organization.

The ideal candidate will have strong experience with Microsoft 365 administration, Microsoft security technologies, identity and endpoint management.

Responsibilities :

• Configure and maintain Conditional Access Policies, multifactor authentication, and access controls.
• Administer Microsoft Intune for endpoint management, device compliance, application deployment, and updates.
• Monitor and manage Microsoft Defender security alerts and respond to security-related incidents.
• Support Microsoft Purview policies, including data protection, retention, and compliance requirements.
• Manage email security, respond to threats, and remediate vulnerabilities.
• Manage Windows endpoints and assist with Windows Server administration.
• Perform system monitoring, patch management, and vulnerability remediation.
• Maintain technical documentation and support IT projects and initiatives.
• Work with internal teams and vendors to ensure reliable and secure technology services.

Required Qualifications :

• Experience administering Microsoft 365 environments.
• Hands-on experience with: Microsoft Intune, Microsoft Defender, Microsoft Purview, Conditional Access Policies, Entra ID (Azure AD), Exchange Online and email security
• Experience managing Windows desktop environments and Microsoft cloud services.
• Knowledge of identity and access management, endpoint security, and Microsoft security best practices.
• Experience with Mimecast, Azure, or Windows Server administration.
• Experience supporting public sector, government, or regulated environments and knowledge of NIST, or other compliance frameworks.
• Microsoft certifications such as Microsoft 365 Administrator, Endpoint Administrator, Identity and Access Administrator, Security Operations Analyst or Azure Administrator

Why Join Us :

• Join a growing IT team supporting modern Microsoft technologies in an environment focused on security, operational excellence, and continuous improvement.