Southeast Public Health: Consolidating Three Microsoft 365 Tenants Without Disruption

Fragmented tenants. Legacy infrastructure. High compliance stakes.

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Southeast Public Health (formerly South East Health Unit) operated across three separate Microsoft environments — kflaph.ca, hpeph.ca, and LGL — each with its own identity model, mail flow, and collaboration footprint. This fragmentation slowed cross-regional collaboration, complicated administration, and increased risk across identity, messaging, and compliance.

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Legacy exchange infrastructure, including Exchange 2010 and Exchange 2020, further constrained cloud adoption and introduced reliability and supportability concerns. Any migration effort needed to preserve service continuity across public health teams while aligning with PHIPA, PIPEDA, GDPR, and AODA requirements.

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This was not a helpdesk engagement. It was an ecosystem rebuild designed to unify identity, modernize messaging, and enable secure collaboration without disruption.

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BITSUMMIT delivered a controlled, zero-downtime tenant-to-tenant consolidation program combining hybrid exchange modernization, identity reconciliation, and phased migration execution. Every phase was structured to minimize risk, preserve service continuity, and ensure operational readiness.

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Hybrid exchange modernization
• Deployed Exchange 2019 hybrid servers in Kingston and Belleville
• Established hybrid coexistence with Microsoft 365 for the LGL environment
• Implemented Hybrid Configuration Wizard and modern authentication for secure mail routing
• Validated coexistence and safely decommissioned legacy Exchange 2010 infrastructure

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Tenant consolidation and identity reconciliation
• Provisioned the new southeastph.ca Microsoft 365 tenant with verified legacy domains
• Identified and resolved more than 250 duplicate UPNs and proxy addresses prior to migration
• Implemented Azure AD Connect staging to support coexistence and controlled synchronization
• Automated aliasing and user cutover sequencing to ensure identity continuity

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Migration execution and platform stabilization
• Coordinated three tenant migrations across more than 15 structured migration waves
• Executed a 30-day delta synchronization strategy to preserve data integrity
• Migrated Exchange Online, SharePoint, OneDrive, and Teams with high fidelity
• Delivered runbooks, rollback plans, and change board-approved cutover schedules
• Validated DNS, mail flow, and compliance policy alignment post-cutover

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Change management and user enablement
• Established weekly change champion networks and daily go-live support huddles
• Delivered bilingual, AODA-compliant training and recorded walkthroughs
• Launched a centralized SharePoint support hub with role-based content
• Monitored adoption telemetry and provided targeted post-migration coaching

The engagement delivered a stable, compliant, and unified Microsoft 365 environment built for long-term public health operations. BITSUMMIT’s disciplined execution ensured continuity of service while eliminating fragmentation and technical debt.

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• Three production tenants consolidated into a single governed Microsoft 365 environment
• Zero-downtime hybrid exchange cutover achieved with full coexistence during transition
• 100 percent of identity conflicts resolved pre-migration with no post-cutover mail issues
• Full staff coverage achieved through bilingual training, change champions, and 30-day hypercare
• Compliance enforced from day one across PHIPA, PIPEDA, GDPR, and AODA

The Path Forward

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With tenant consolidation complete, Southeast Public Health is now positioned to advance cloud-native service delivery, strengthen security policies, and expand automation across Microsoft 365. Optional post-hypercare support, modular training, and compliance refinement provide a clear roadmap for continued maturity without vendor lock-in or operational risk.

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BITSUMMIT’s delivery established a unified foundation for collaboration, governance, and scalable public health operations.

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Modern collaboration starts with a unified platform
Partner with BITSUMMIT to consolidate, secure, and modernize Microsoft 365 environments across Canada.

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