What Doesn't Survive a Google Workspace to Microsoft 365 Migration

Gmail filters, Apps Script automations, Google Forms and Sites, Drive version history, every shared Drive link, and your Google Chat history: none of those arrive in Microsoft 365. Every migration quote answers "how do we move the mail and files?" Almost none answer the question that causes the pain six weeks later: what arrives broken, and what never leaves at all. Even the best third-party tooling moves your content and leaves the connective tissue behind. Here is the full inventory, workload by workload.

First, the tool question

Three options dominate this route: Microsoft's own Migration Manager, BitTitan MigrationWiz, and CloudM Migrate. What each one costs, and what the paid ones buy that the free one does not, is priced further down this page. The part vendors will not put on a pricing page is that they differ less than their marketing suggests. All of them move the same core content competently, and the hard losses below are not tool limitations. They are platform differences, and no license fee makes them go away.

What survives cleanly

• Mail, with attachments and folder structure derived from your labels.
• Calendar events, including recurrences and attendee lists.
• Personal contacts.
• Drive files, including Google Docs, Sheets, and Slides converted to Word, Excel, and PowerPoint on the way through.
• Shared Drive content, mapped to SharePoint libraries or Teams, usually licensed per drive on top of the per-user fee.

If your environment is mail, calendars, contacts, and ordinary files, the move is a known route. The trouble lives in the next two lists.

What survives, but damaged

• Labels become folders, and the model does not fit. Gmail lets one message carry five labels; Outlook puts a message in one folder. Tools either duplicate the message into every matching folder or pick one. The Social, Promotions, and Updates category tabs do not come at all, and snoozed or scheduled messages arrive as ordinary mail with their snooze and schedule state stripped.
• Contact groups arrive unsorted. The group folders get created at the destination, and then the contacts land in the top-level folder anyway. Somebody re-sorts them by hand, or nobody does.
• Converted Sheets lose their cleverness. QUERY, IMPORTRANGE, and GOOGLEFINANCE have no Excel equivalent, and any script attached to a spreadsheet dies in conversion. A finance team that runs on clever Sheets needs each one tested, and the clever ones rebuilt.
• Sharing survives only inside the company. Internal permissions map reasonably well. External collaborators are dropped, and every "anyone with the link" share dies silently, which brings its own line item below.
• Calendars carry their plumbing problems with them. Conference room calendars usually do not migrate and get rebuilt as Microsoft room resources. Event descriptions can drop on the way through. And every recurring meeting still contains a Google Meet link that will keep working and keep taking people to Meet long after you have paid for Teams. Each standing meeting needs its link replaced by hand.
• Signatures and out-of-office messages stay behind. Plan for everyone to rebuild both on day one.

What never leaves

• Gmail filters. Years of carefully built rules stay in Gmail. Power users rebuild them as Outlook rules by hand, and the people with 80 filters are always your most vocal employees.
• Anything built on Apps Script, Forms, Sites, or AppSheet. There is no migration path for any of these. The approval flow someone automated in 2021, the customer intake form, the intranet on Google Sites: these are rebuild projects in Power Automate, Microsoft Forms, and SharePoint, and they belong on the project plan as named line items with owners.
• Drive version history, and usually comments. Tools migrate the latest version of each file. Years of revision history stay behind, and comment threads range from partially preserved to gone depending on the tool. Plan as if both are gone, and export anything contractually important first.
• Every shared link in existence. Each Drive URL pasted into chats, wikis, bookmarks, and customer emails dies with no redirect. This is the single most common post-migration complaint, and the fix is communication before cutover, because there is no fix after.
• Google Chat and Spaces history. A handful of niche tools claim partial Chat-to-Teams moves; in practice, plan to archive the history for reference and start Teams clean. Meet recordings are ordinary files in Drive, so those do move.
• Google Groups as living things. The addresses can be recreated as distribution lists or shared mailboxes, but a collaborative inbox's conversation history and assignment state have no clean destination, and any Drive permission granted to a Group has to be re-modeled.
• Google Vault holdings. Data under legal hold has to be exported and preserved with chain of custody intact before anything is decommissioned, and the holds re-established in Microsoft Purview. If your company has ever been near litigation, this is a workstream of its own.
• Files owned by personal Gmail accounts. The founder's early documents shared in from a personal @gmail.com are legally that person's account, and no tool can touch them without that account's consent. Find them early; they are always the important files.

The migration plan this list implies

A clean Google exit is mostly an exercise in honesty before cutover. The rebuild items (filters, signatures, room calendars, Apps Script, Forms) go on the plan as named tasks with owners instead of being discovered as surprises. The communication pack tells everyone which links die and what to re-pin before they lose access, with a pilot group proving it a week ahead. And the freeze window keeps people from editing documents that have already moved. This is also why the migration intake asks about Apps Script, Vault, and Shared Drives before quoting a number: each one moves real work from "migration" to "rebuild," and a quote that ignores them is a quote you pay twice.

Where to go from here

Standard scope for a Google exit means up to about 50 users, under 1 TB across Gmail and Drive, minimal Shared Drives, no SSO dependencies, nothing built on Apps Script, and no Vault holds. The $3,500 above assumes that, and anything outside it is scoped before a number is quoted. If you are still weighing whether to move at all, start with the Microsoft 365 vs Google Workspace comparison. If the move is decided and the open question is where Drive content should land, OneDrive vs SharePoint vs Azure Files settles that before the first batch runs. Or talk through the problem and get a fixed number within one business day.