Migrating from Microsoft 365 to Zoho Workplace: Coexistence as the control layer

Migrating from Microsoft 365 (M365) to Zoho Workplace is more than a switch in tools—it’s a shift in how employees engage with their digital workspace and how IT admins manage the backend infrastructure. The process is mission-critical and offers a rare opportunity to recalibrate digital assets, reassess workflows, and realign security and governance policies.

In enterprise environments, where migration typically occurs in phased batches, a coexistence phase often emerges where both M365 and Zoho Workplace run in parallel. This period gives admins and stakeholders a strategic window to compare, validate, and optimize system architectures, access controls, and operational workflows before making a complete transition. This article walks you through the key stages, control points, and considerations that define a successful migration, especially during the coexistence phase.

The user experience shift

Migrating from Microsoft 365 to Zoho Workplace is a shift to a web-first, integrated ecosystem for communication, collaboration, and productivity.

• New app names and navigation: Outlook becomes Zoho Mail, Teams becomes Zoho Cliq, and Office apps are replaced by Zoho Writer, Sheet, and Show.
• Web-centric workflow: Most work happens in the browser or mobile apps, reducing reliance on desktop clients.
• Unified experience: A single launcher brings together mail, chat, files, meetings, and more—minimizing app switching and simplifying daily workflows.

App mapping

Mail admin experience: What changes?

Behind the scenes, the migration is a major shift for IT admins who must manage delivery, authentication, policies, and user support.

The migration process ensures that all critical components needed for business continuity and operational integrity are carried over:

• User directory: User accounts, groups, departments, roles, and access permissions
• Mail data: Emails, folders, filters, aliases, mailbox settings, and retention rules
• Groups and distribution lists
• Files and documents: From OneDrive/Share Point to ZohoWorkDrive
• Tasks and notes: Where supported
• Authentication and access controls: SSO methods, MFA, basic policy mappings
• Security and compliance settings: Retention policies, audit trails (with some manual reconfiguration)
• APIs and integrations: Custom connectors, scripts, and third-party app configurations (selectively rebuilt if needed)
   

Migration stages

Migrating from Microsoft 365 to Zoho Workplace is a phased process—especially in mid-size to large organizations. It moves through well-defined stages, each governed by strict control points to ensure accuracy, traceability, and rollback safety.

Planning

The migration team begins by defining the overall migration scope—total user count, timeline, batch sizing, and delivery strategy (cutover or staged).

Key planning areas include: 

• Migration architecture: Decide how users, mail flow, and services will transition in phases. 

• Coexistence design: Define how long both platforms will run side by side, including directory synchronization (e.g., AzureAD ↔ Zoho Directory), mail flow routing, calendar and contact coexistence. 

• Authentication and security alignment: MapOut SSO, MFA, DLP, and retention policy equivalents between systems. 

• Change control strategy: Establish freeze points, rollback windows, and blackout periods. 

• User communication and support plan: Prepare onboarding guides, communication templates, and help desk escalation paths for each migration phase.
   

Configuration

Once planning is complete, each migration batch goes through a dedicated configuration phase to prepare the environment for a safe and verifiable transition.

Key configuration activities include: 
 

• Directory sync and provisioning: Set up or update Zoho Directory Sync to reflect user, group, and department mappings. Provision Zoho accounts, roles, aliases, and mailbox settings for the batch. 

• Mailflow and coexistence setup: Configure mail routing rules for split or dual delivery between Microsoft 365 and Zoho Workplace. Apply MX,SPF, DKIM, and smart host settings as needed.

• Authentication and policy alignment: Implement SSO, MFA, DLP, and retention policies aligned with organizational standards.

• Coexistence controls: Ensure directory-level visibility (GAL), consistent mail routing, and optionally configure calendar/contact sync or forwarders for dual environments. 

• Pre-migration freeze: Set after configuration to prevent changes before migration, ensuring clean data capture.
   

Pilot migration

The pilot phase tests the migration setup with a small, representative user group before scaling to full batches.

• Mailflow validation: Confirm delivery, group/alias mapping, and routing between Microsoft 365 and Zoho Workplace.
• Security checks: Verify DLP, access controls, and retention behavior.
• Access and login testing: Validate SSO, device access, and app compatibility.
• Admin visibility: Check logs and reports for audit completeness.
• Rollback window: Allow safe return to Microsoft 365 if needed, with no data loss.
   

Coexistence

The coexistence phase begins after the pilot or first batch is live and continues until the final batch is fully migrated. During this phase, both Microsoft 365 and Zoho Workplace operate in parallel, requiring tight coordination and monitoring.

• Mailflow continuity: Ensure that dual or split delivery mechanisms are correctly routing messages across platforms.
• Directory synchronization: Maintain up-to-date user and group data between identity systems to support GAL visibility and routing accuracy.
• Calendar and contact coexistence: Configure contact sync tools and shared calendars as required by the organizational workflows.
• Coexistence closure: The phase ends when the final user batch is migrated, directory sync is disabled, and all services are centralized in Zoho Workplace.

Velocity migration

Once the pilot is validated and approved, the organization proceeds with full-scale migration in batches; each batch is executed using a repeatable, controlled process.

• Batch preparation: Finalize directory sync, routing setup, and user provisioning for each wave.
• Freeze enforcement: Lock mailbox and permission changes to preserve data consistency.
• Migration execution: Migrate mailboxes and settings to Zoho Workplace using validated tooling.
• Rollback readiness: Keep a rollback option open between migration and active usage.
• User onboarding: Provide batch-specific guidance, credentials, and support channels to ensure smooth adoption.
   

Coexistence: The critical transition layer

• This is the phase where the source of truth—identity, mail flow, and policy—shifts from Microsoft 365 to Zoho Workplace.
• The longer this dual state lasts, the higher the cost in support load, confusion, and decision delays.
• Zoho shortens coexistence with tightly integrated tools—directory sync, dual delivery, policy control, and rollback—all managed from a single console. Confidence in these controls ends coexistence faster.

Enterprise email migration to Zoho Workplace leverages a Zoho-powered coexistence framework that keeps legacy systems—Microsoft 365, Exchange, and Google Workspace—running in parallel until every mailbox and user service completes transition. This approach ensures uninterrupted message delivery, consistent identity management, and seamless collaboration throughout a phased rollout.

Key components of Zoho’s coexistence and interoperability framework:

• Mail flow architecture: With Split-Delivery and Dual-Delivery Connectors, incoming mail lands on the primary platform (MX target) and any unknown recipients are securely routed to Zoho’s inbound gateway. Outbound messages follow the reverse path through Zoho’s outbound gateway or the primary platform’s security layer.
• Identity synchronization and provisioning: Sync On-Prem AD and Azure Entra ID with Zoho Directory via SCIM/API for unified provisioning/deprovisioning, and enable seamless SAML-based SSO across Zoho Workplace and connected apps.
• Contact synchronization: Perform a one-time bulk import of Microsoft GAL users and external contacts into Zoho Organization Contacts (and vice versa), then run scheduled delta syncs to capture creates, updates, and deletes—honoring master-ownership and automated conflict resolution.
• Calendar federation: Enable free/busy lookups and cross-platform meeting invites via Microsoft Graph and CalDAV APIs so users can schedule across domains without switching clients.
• Security and compliance enforcement: Enforce DLP and ATP policies plus conditional access/MDM uniformly across both Zoho and legacy platforms.

Coexistence architecture

Scenario
Email delivery (split delivery) and identity sync: Office 365 ↔ Zoho Workplace coexistence.

Office 365 and Zoho Mail operate side-by-side during a phased migration. Inbound mail first lands in Exchange Online—using a split-delivery connector for unknown recipients—before falling back to Zoho’s inbound gateway, where it’s scanned, routed, and delivered. 

Outgoing messages follow the reverse path via Zoho’s outbound gateway or through Defender ATP and DLP in Microsoft 365. Concurrently, On-Prem AD and Entra ID sync bi-directionally into Zoho Directory, unifying user identities and enforcing consistent SSO and mobile device policies across both platforms. Together, these components ensure seamless mail flow, centralized security, and zero downtime user onboarding throughout the coexistence phase.

Conclusion

A successful migration to Zoho Workplace isn’t defined by how fast users are moved; it’s defined by how precisely each phase is executed. Planning sets the stage, configuration defines the rules, and coexistence ensures controlled execution, enabling an interruption-free transition from Microsoft 365 to Zoho Workplace by managing routing, identity, access, and policy enforcement while users migrate in batches. 

The tighter these are managed, the shorter and cleaner the coexistence period becomes. Zoho’s integrated tools—directory sync, dual delivery, unified policy control, and rollback handling—reduce the overhead and complexity that typically prolong coexistence. A well-executed migration ends not when the last mailbox is moved, but when coexistence is no longer required, and the environment runs entirely on Zoho, without compromise.

This article is co-authored by Sandeep Kotla and Vignesh S.

Sandeep is an accomplished inbound marketer at Zoho Corporation, specializing in digital workplace strategies, digital transformation initiatives, and enhancing employee experiences. Previously, he handled analyst relations and corporate marketing for Manage Engine (a division of Zoho Corp) and its suite of IT management products. He currently spends most of his time re-imagining and writing about how work gets done in large organizations, reading numerous newsletters, and Marie Kondo-ing his inbox.

Vignesh works as a Marketing Analyst at Zoho Corporation, specializing in content initiatives and digital workplace strategies. He's a passionate creator with a penchant for marketing and growth. In his free time, you can see him shuffling between books, movies, music, sports, and traveling, not necessarily in the same order.