Indicative results from Mycelium 365 Google Workspace to Microsoft 365 migrations across 20–200 seat Australian, New Zealand and US environments.
Discovery, tenant build, mail and Drive migration, cutover and hypercare; 5 weeks typical at 50 users
Mail, calendar and contact counts reconciled per mailbox before sign-off
Co-existence routing means no period where mail is unreachable
Floorwalker support, ticket priority and role-based Outlook, Teams and OneDrive enablement
Indicative ranges based on delivered projects. Actual figures depend on mailbox sizes, Drive volume, shared drive count and training scope.
A platform migration is a data integrity exercise as much as a technology project. We baseline the source tenant during discovery, reconcile counts at every batch, and report the same metrics 30 days after cutover so the business has evidence rather than assurances.
| Metric | Google Workspace baseline | Post-migration target | How it is measured |
|---|---|---|---|
| Mail items migrated | Source item count per mailbox | 99.9%+ reconciled, exceptions itemised | Per-batch migration reports vs source counts |
| Drive data migrated | Total GB and file count across My Drive and shared drives | Full parity with a documented exception list | OneDrive and SharePoint library reconciliation report |
| Sharing permissions preserved | Internal and external share inventory | 95%+ automatic, remainder reissued manually | Pre-cutover shared drive validation sign-off |
| Mail unreachable time | n/a | Zero — co-existence routing during cutover | Mail flow monitoring across the cutover window |
| Migration tickets per user | n/a | Under 0.5 in the first fortnight | Service desk ticket tagging during hypercare |
| Security posture at go-live | Google admin controls, variable MFA coverage | 100% MFA, Conditional Access and Intune baselines enforced | Entra ID sign-in reporting and Intune compliance |
1. Hidden Drive sprawl. Personal My Drive folders often hold business-critical content that nobody has catalogued, and orphaned files belonging to departed staff are common. Discovery reports data volume, ownership and orphan status per user so nothing is stranded when Google licences are cancelled.
2. Google-native file conversion. Docs, Sheets and Slides do not move as-is. Complex Sheets with Apps Script, macros or heavy formula logic are identified during discovery and converted, rebuilt or intentionally left in place with a documented decision — never discovered as broken after cutover.
3. External sharing breakage. Client and supplier links into shared drives will break unless they are inventoried and reissued as Microsoft 365 sharing links. We produce that inventory before cutover and coordinate reissue with the owning teams.
4. Third-party app dependencies. Applications authenticating via Google SSO, plus scanners, CRMs and line-of-business tools sending mail through Google SMTP relay, all need re-pointing to Entra ID and Exchange Online. Missing one is the classic cause of a silent post-cutover outage.
5. Change fatigue. The technical migration is usually easier than the behavioural one. Role-based enablement, quick-reference guides for the common Gmail to Outlook questions, and floorwalker support in cutover week keep adoption — and the service desk queue — under control.
Most organisations consolidating onto Microsoft 365 do so for the same reasons: tighter integration with the productivity tools their customers, suppliers and accounting platforms already use; access to enterprise-grade security through Defender, Entra ID and Intune without bolting on third-party tooling; and licensing efficiency when bundles like Microsoft 365 Business Premium replace Google Workspace plus a separate identity, MDM and email security stack. Microsoft 365 also gives organisations a clearer alignment to the ACSC Essential Eight — application control, patching, MFA and admin privilege restriction — through native Microsoft tooling rather than Google add-ons. Data residency is preserved through Microsoft's Australian regions, and Teams, SharePoint and OneDrive provide a single collaboration fabric instead of the Meet, Drive and Chat split that complicates governance.
Every Mycelium 365 migration begins with discovery — a full user inventory, mailbox sizing, Drive footprint, shared drive mapping, calendar resource audit and dependency review for any apps that authenticate against Google Workspace identity. From there we move to tenant build: domains, Entra ID, Conditional Access, MFA, Intune baselines, Defender for Office 365, SharePoint information architecture and licensing assigned to match each role.
Mail co-existence is established so Gmail and Exchange Online can route between each other during the cutover window, then mailboxes, calendars and contacts are migrated in waves. Drive content is moved in parallel — personal files to OneDrive, shared drives to SharePoint document libraries — with permissions and external shares preserved.
DNS cutover flips mail flow to Microsoft 365 at the agreed window, after which users move fully to Outlook, Teams and OneDrive. We close out with decommissioning of Google Workspace licences, including timing guidance so you stop paying for both platforms once cutover is complete.
Most Australian Google Workspace to Microsoft 365 migrations complete in 4 to 8 weeks end-to-end. A 50-user organisation with a clean Drive footprint and standard mail history typically lands inside 5 weeks including tenant build, data migration, DNS cutover and 30 days of hypercare.
Timeline is driven by total mailbox size, Drive data volume, the number of shared drives, whether any business apps depend on Google identity, and how much hands-on user enablement is required for Outlook, Teams and OneDrive.
Mycelium 365 includes a 30-day hypercare period after cutover — daily check-ins, priority ticket handling, floorwalker support for the first week, and end-user training sessions — before the environment transitions into ongoing managed services.
A structured four-phase approach to move from Google Workspace to Microsoft 365.
Audit your Google Workspace environment, map users, mailbox sizes, Drive volumes and dependencies, and produce a phased migration plan.
Build your Microsoft 365 tenant — domains, licensing, Entra ID, Conditional Access, Intune baselines and security policies — before any data moves.
Migrate Gmail, calendars, contacts and Drive content in batches with validation at every stage and parallel running to protect business continuity.
Switch DNS, onboard users to Outlook, Teams and OneDrive with role-based training, and run 30 days of hypercare post cutover.
Every layer of your Google Workspace environment, mapped and migrated to Microsoft 365.
Gmail to Exchange Online — full history, labels mapped to folders, filters and shared calendars migrated with metadata intact.
Personal Drive content to OneDrive; shared drives to SharePoint document libraries, with permissions and external shares preserved.
Google Contacts and Groups migrated to Exchange and Microsoft 365 Groups with membership and ownership maintained.
Post-migration hardening with Entra ID Conditional Access, MFA enforcement, Defender for Office 365 and Intune device compliance.
