"We currently use Microsoft 365, but we want to switch to Google Workspace for both cost efficiency and usability. However, we're terrified that past emails might disappear or that incoming mail will stop delivering mid-migration, so we can't bring ourselves to take the leap." In migration consultations, this anxiety arises almost without fail. The decision to switch tools is firm, yet because email is something that immediately halts business operations if interrupted, teams freeze at the final step. That hesitation is completely understandable. When migrating, the staging required to switch without disrupting existing operations demands far more vigilance than merely provisioning the new environment.
There is good news: in May 2026, a free import tool for ingesting data from Microsoft 365 was integrated natively into the Google Workspace Admin Console. Requiring neither additional licenses nor dedicated server provisioning, it can be launched directly from the setup screen immediately after verifying domain ownership and activating Gmail. This certainly lowers the barrier to email migration. However, easier tooling does not mean migrations cannot run into trouble. In this article, we distinguish between what the tool covers and the critical points that still require human architectural design, outlining from a custom development perspective the steps needed for a smooth migration.
What the new free tool simplifies and what still requires attention
First, it is vital to understand accurately what this built-in import tool does and does not do as of 2026. Proceeding under false assumptions can lead teams to assume everything is taken care of, causing them to overlook unmigrated assets.
The three areas reliably supported are emails, calendars, and contacts. Data for these services on Microsoft 365 can be ingested directly into Google Workspace via the cloud. Given that daily operations revolve around email and scheduling, having native tool support for these areas is a major milestone.
On the other hand, OneDrive, Teams, and SharePoint Online are merely listed as "planned for future support," with no release timeline announced. This means data stored in OneDrive as a file server replacement, message histories in Teams, and SharePoint sites fall outside the native tool and require separate solutions. Overlooking this creates an incomplete state where emails have migrated, but files remain trapped in the legacy environment. Designing file operations on the Google Workspace side alongside the migration ties directly into the perspectives discussed in our article on Google Drive sharing settings.
If you are still weighing the foundational choice between Google Workspace and Microsoft 365, reading our comparison article between Google Workspace and Microsoft 365 beforehand will help keep your decision grounded.
Three critical pitfalls where migrations fail
Where real trouble emerges during a migration is not usually the raw data itself, but rather the staging of the cutover. From our extensive hands-on experience in custom development projects, accidents consistently concentrate around three critical pitfalls.
The first is the timing of the MX record switch. The moment you point your MX records to Google to route mail, all new incoming emails flow to Google. If cut over before destination user accounts are provisioned or before legacy email imports have finished, new messages can be lost in limbo, causing widespread confusion over whether to check the old or new inbox. This single step is by far the most error-prone in the entire migration workflow.
The second is skipping test migrations. Executing a company-wide production migration without prior testing ensures that any unexpected glitch affects the entire organization. Conducting a pilot migration with a small test group to verify that emails transfer properly without garbled text, missing attachments, or unexpected behavior before moving to production is essential. Rushing this step almost inevitably leads to severe operational fallout later.
The third is an all-at-once migration. Attempting to migrate everyone simultaneously in an organization with substantial data volume clogs the migration pipeline and makes isolating root causes difficult when issues emerge. Migrating progressively by department or group keeps business disruption minimal and bounds the blast radius if an anomaly occurs.
| Choke point | Common pitfall | Mitigation via custom development |
|---|---|---|
| MX cutover timing | New emails stranded / Confusion between old and new | Cut over only after user provisioning and historical email imports are complete |
| Skipping test migration | Encoding issues or missing attachments discovered company-wide | Validate in advance with a small group before production rollout |
| All-at-once migration | Pipeline bottlenecks / Inability to isolate issues | Stage phased rollouts by department |
As shown in the table, incidents occur not because data cannot be transferred, but because sequencing is mishandled. That is why migration architecture and execution management matter far more than the tools themselves.
Our case study: When "we can do it ourselves with the tool" stalled halfway
Here is a concrete example. We received a mid-migration inquiry from a specialized trading company (company name withheld), who told us: "We started migrating from Microsoft 365 on our own after hearing about the free migration tool, but we grew uneasy halfway through and ground to a halt." While they had managed to import emails, when it came time to switch the MX records, they froze out of fear, unsure whether it was truly safe to flip the switch and whether they could roll back if something went wrong.
When we evaluated the situation, pausing was the right decision. Historical email imports were still pending for some users, and destination accounts for shared mailboxes (such as info@ addresses) had not been created; flipping the MX switch in that state would have guaranteed lost emails to their main company address. Furthermore, client-specific files stored in OneDrive fell outside the native tool, creating an impending split where emails would migrate while files remained stranded in the old environment. While undertaking the migration internally was commendable, they had missed the critical staging sequence of what must be completed before switching MX records.
We began by auditing the full scope of migration assets—whose emails, which shared addresses, and which files—ensuring that past emails and destination accounts were fully ready for all users, while arranging a separate migration pathway for OneDrive files. From there, we switched MX records incrementally starting from departments with minimal business impact, confirming inbound receipt at each phase. As a result, the transition was completed without dropping a single email, including messages sent to the main contact address. What we applied was not complex engineering, but simply determining the correct sequence and validating step by step. The true value of migration support lies precisely in that rigorous sequencing and verification.
When planning a migration, start with an inventory
If you are considering migrating to Google Workspace, starting with an inventory of what needs to be moved is far more effective than researching tool documentation. All user mailboxes and historical archives, main and shared addresses, calendars, contacts, and files excluded by native tools (OneDrive, SharePoint, Teams)—only when these are cataloged can you determine what the built-in tool handles, what requires separate solutions, and in what sequence to switch MX records. Conversely, jumping into action without this comprehensive roadmap leads directly to stalling midway, just as in the case study above.
If you are worried about migrating past emails without data loss, find yourself stuck on the MX cutover decision after starting in-house, or want to migrate all data including OneDrive and SharePoint seamlessly, please reach out through GleamHub's contact page. We will audit your current Microsoft 365 usage, distinguish between what native tools cover and what requires dedicated solutions, design a bulletproof sequence to ensure not a single message is missed, and support you from cutover through long-term adoption.
Sources
- The new feature that completes Microsoft 365 to Google Workspace migration in "minutes" (May 2026 release) - Bring It On! Google Workspace
- Migrate from Microsoft to Google Workspace - Google Workspace Learning Center
- Steps and tips for migrating from Microsoft 365 to Google Workspace - TS Cloud Inc.
