Office 365 to Google Workspace migration

Exchange Online to Gmail is a well-trodden path. Folders become labels, the folder hierarchy is preserved as nested labels, and read state, flags and attachments come across. Rules and out-of-office settings do not transfer and are rebuilt, which for most users takes under five minutes and for a small number of power users takes a scheduled call.

Files are where the project needs your attention. SharePoint models permissions as an inheritance tree with breaks; Google models them as membership of a shared drive plus per-item exceptions. Those two models do not map one to one, so somebody has to decide where the boundaries sit. We produce that mapping as a spreadsheet and walk through it with each department owner before anything moves.

Teams chat history has no Google destination. Google Chat exists, but Microsoft does not expose an export path that preserves threaded chat into a third-party platform in usable form, so plan for chat history to be archived in Microsoft rather than migrated. The same applies to Planner boards, Power Automate flows and any Power App built against a SharePoint list.

Those are rebuild items, not migration items, and they belong in the project plan with named owners. Pretending otherwise is how migrations acquire a bad reputation: the mail moves fine, and then in week three someone discovers the approvals flow that quietly ran the purchase order process.

You will pay for both platforms for a period. The goal is to keep that period to weeks rather than months. Microsoft's annual commitment terms mean most organisations cannot simply stop paying mid-term, so we plan the cutover date against the Microsoft renewal date wherever the calendar allows.

Where the renewal is far off, the cheaper answer is often to downgrade remaining Microsoft seats to the lowest tier that keeps archive access rather than cancelling outright. That keeps a read-only path to anything not migrated without paying full seat price for a platform nobody logs into.

Friday evening the MX records change and mail begins landing in Google. Overnight the final mail delta runs. Saturday is Drive and SharePoint content plus permission application. Sunday is verification: a sample of users across departments logs in, checks mail, opens a shared file, and accepts a calendar invite. Monday morning we are on site or on call for the first four hours.

The rollback position is simple and worth stating explicitly: until the final delta completes, the Microsoft tenant remains intact and authoritative, and reverting is an MX change back. After the final delta, rolling back means losing mail received in Google, so that is the point of no return and it is scheduled deliberately.