Exchange to Microsoft 365 Migration for a Public-Sector Education Organization

Challenge

A public-sector education organization needed to modernize its email environment by migrating from on-premises Microsoft Exchange to Microsoft 365. The environment included Exchange Server, public folders, existing mail flow dependencies, and the need for a controlled migration path that preserved coexistence during the transition. Key technical considerations included mailbox migration sequencing, public folder access, hybrid mail routing, Autodiscover behavior, user identity alignment, and coexistence between Exchange Online and the on-premises Exchange server.

Approach

Safari Micro implemented a hybrid Exchange migration strategy across structured phases: (1) server readiness — updating Exchange 2013 to a supported cumulative update level and validating Autodiscover connectivity and UPN configuration; (2) hybrid configuration — enabling Hybrid Exchange in Azure AD Connect, configuring Exchange Hybrid and hybrid mail flow, and establishing Office 365 mail connectors; (3) migration testing — creating and validating the migration endpoint, assigning licensing, and testing mailbox migration to Exchange Online and back; (4) coexistence validation — validating free/busy calendar coexistence, mail flow, and hybrid public folder access; (5) phased migration — migrating users in batches and migrating public folders after mailbox completion; and (6) cutover and cleanup — cutting over mail flow to Exchange Online Protection, updating SPF and Autodiscover DNS records, and delivering documentation and knowledge transfer.

Results

• Modern Microsoft 365 email platform delivered for the organization
• Hybrid coexistence maintained throughout the migration period
• Validated mail flow between on-premises Exchange and Exchange Online
• Calendar free/busy functionality preserved during transition
• Public folders migrated after mailbox migration completion
• Mail flow cut over to Exchange Online Protection after validation
• SPF and Autodiscover DNS records updated to support Microsoft 365 email services
• Administrative documentation and knowledge transfer delivered for ongoing support