*Key ResponsibilitiesActive Directory, DNS, and DHCP* * Support, maintain, and monitor the health of the *Active Directory* infrastructure, ensuring high availability and optimal performance. * Manage and troubleshoot *DNS and DHCP* services, including replication, zone configurations, and IP address management. * Implement Group Policies (GPOs), domain controller deployments, and schema updates as needed. *Microsoft Exchange & Messaging* * Design, implement, and administer *Microsoft Exchange* environments (on-premises and/or hybrid). * Provide Tier 3 support for messaging, mail flow, security, and performance issues. * Plan, coordinate, and execute system upgrades, migrations, patches, and service pack installations. * Ensure messaging systems meet compliance, backup, and retention requirements. *Lync / Skype for Business / Unified Communications* * Support and troubleshoot *Lync/Skype for Business* environments, including voice, conferencing, presence, and integration with Exchange and AD. * Monitor system health and performance, ensuring reliable unified communications services. *Systems Maintenance & Security* * Perform routine network/system maintenance including applying *patches, hotfixes, service packs, firmware updates*, and configuration changes. * Implement and enforce *security configurations* to meet compliance and best practice standards. * Develop documentation …