Job email-google-workspace-to-microsoft-365-mailboxes · revised 11 October 2026
Move up to five Google Workspace mailboxes into Microsoft 365, mail only
Copy up to five Google Workspace mailboxes into Microsoft 365 with a pilot mailbox first, switch incoming mail safely, and prove folder counts, sampled messages and new mail match.
You might be seeing
- You are not sure what happens to Gmail labels when mail moves to Outlook-style folders
- Switching MX records feels risky: you fear losing mail in the middle
- Someone suggested exporting to files and importing them, and you want a controlled copy instead
- Old and new mailbox counts need to match before the old account is closed
No passwords, keys, card details or admin invites needed to start.
What usually happened
Google Workspace organises mail with labels, not folders, and a single message can carry several labels. Changing the MX records moves only new mail, so the old messages stay behind unless they are copied. A copy that starts before the Microsoft 365 users exist and before mail routing between the two systems is arranged fails or leaves gaps, and Microsoft's own migration needs administrator consent and a mail-routing subdomain on each side. Microsoft documents how to leave folders and labels out of the copy, but it does not say how Gmail labels become folders or how a message with several labels is copied, so that is observed on a pilot mailbox before the rest are copied.
Who it’s for: Owner of a small business that has decided to leave Google Workspace for Microsoft 365 and needs the existing mail to come along.
Usually starts when: A licence renewal, a client or insurer asking for Microsoft 365, or a merger means mail must move without losing years of messages or missing new ones.
The result: Up to five mailboxes arrive in Microsoft 365 with folder counts compared to the old ones and every difference explained, sampled messages found, how multi-label messages arrived recorded from the pilot, new mail reaching the Microsoft 365 mailboxes, and the Google mailboxes untouched until you close them.
Check whether this job fits
Five questions, about two minutes. Your answers stay on this page unless you choose to email them.
Checks you can run yourself
See which provider receives your mail today
On a Mac or Linux terminal, run this read-only lookup with your own domain, or use any public DNS lookup website.
dig +short MX yourbusiness.co.ukLook for: Names from Google mean mail still goes to Google Workspace. After the switch they should be the Microsoft 365 value shown in your Microsoft admin centre and nothing else.
What you get
- The inventory, the exclusion list and a pilot note recording how labelled and multi-label messages arrived, written in plain English
- A per-mailbox comparison of folder and message counts before and after, with every difference explained, and the list of sampled messages with where each was found
- Steps for the domain holder to switch MX records, and for you to confirm each mailbox
- A list of anything that did not move and what to do about it
- A record that the migration access has been removed after sign-off
Included
- Up to five user mailboxes at one domain, each up to 10 GB of mail
- An inventory of mailboxes, aliases, groups, filters and the domain's mail records
- A pilot on one mailbox before the rest, to observe how Gmail labels arrive in Microsoft 365, including messages that carry several labels and, if any folders or labels are left out of the copy, messages that carry both a left-out and a kept label
- A Microsoft migration batch started from Exchange Online PowerShell, the route that offers folder and label exclusions, copying mail from Google Workspace into mailboxes you have created at Microsoft 365, with an initial copy and further syncs as close to the switch as the batch allows
- The MX switch by the domain holder, then checks of new incoming mail, outgoing mail and old-folder access for each mailbox
Not included
- Calendars, contacts, Drive files, shared drives, Google Groups, Chat history or sites: ask for a separate quote if you want them moved
- Creating the Microsoft 365 tenant, buying licences or creating the user mailboxes: those are yours to provide
- Vacation and automatic-reply settings, which Microsoft's documentation lists as not migrated
- Removing duplicates or reorganising folders after the copy: if the pilot shows the same message in more than one folder, a tidy-up is a separate quote
- More than five mailboxes, or any mailbox over 10 GB of mail
- Archiving, legal discovery or retention guarantees
How we know it’s done
Agreed with you before work starts. Each check produces evidence you keep.
For each mailbox, the folder and message counts at Microsoft 365 are compared with the Google mailbox label by label, and every difference, such as an item on the agreed exclusion list, a duplicate the pilot showed or an oversize message, is explained in writing.
Evidence: A per-mailbox comparison table before and after, with a reason against each difference
For each mailbox, a sample of 20 messages (all of them if the mailbox has fewer than 20 multi-label messages, topped up with single-label ones) is located at Microsoft 365 by sender, date and subject. None is missing unless it carries a label on the agreed exclusion list, and every such message, every folder holding a copy and every duplicate is listed. The pilot note records, before the other mailboxes are copied, how multi-label messages arrived and which option you chose.
Evidence: The sample list with the folder or folders where each message was found, and the pilot note
After the MX switch, a test message from an outside provider to each mailbox arrives in Microsoft 365, and a reply from each mailbox reaches the outside address.
Evidence: The two messages and their headers for each mailbox
dig +short MX yourbusiness.co.ukAfter sign-off the migration access is removed: the service-account key is deleted, its delegation entry is revoked and the migration endpoint is removed.
Evidence: Screenshots of each console after removal, taken with your administrator
Sign-off. You sign off after each mailbox owner has checked a few old and new messages and the comparison table, then confirm in writing before the Google mailboxes are closed.
If it fails. If a mailbox cannot be moved within the agreed checks, it is listed with the reason and left in Google, and £79 (one fifth of the £395 fixed price) is deducted for each mailbox that does not pass.
When it fits, and when we stop
It fits when
- You hold an administrator account at both providers, or the holders will follow our steps and approve what Microsoft's migration needs
- Your Microsoft 365 domain is verified and a mailbox already exists for each person to be moved
- You can keep the Google Workspace subscription active for at least 30 days after the switch
We stop and tell you if
- The Microsoft 365 tenant enforces retention or archive policies that move or delete messages during the copy, so counts cannot be compared fairly
- More than a few messages exceed the size limit set for your Microsoft 365 mail flow, which Microsoft documents as 35 MB by default
- The Google administrator cannot or will not approve the access that Microsoft's migration needs
- The switch has to happen within hours, with no time for a catch-up copy
- After the pilot, you cannot accept how multi-label messages arrive and none of the options (accept it, leave a label out, or a separately quoted tidy-up) suits
What could go wrong
The copy only reads the Google mailboxes and does not delete their mail, so nothing is lost if a step fails. Before the MX switch the domain holder can stop. After it, the old MX values can be restored, though mail delivered in between stays where it landed and must be collected from both places.
Scroll the table sideways to read it all.
| Risk | How we handle it |
|---|---|
| Messages that carry several labels end up in more than one folder, or are left out by an exclusion. | Microsoft does not document how they are copied, so the pilot mailbox shows it before the rest are copied, and a sample of messages is located in every mailbox afterwards. |
| Retention or archive policies in the new tenant make messages look missing. | We ask about those policies first and stop if they would make the comparison meaningless. |
| Mail arrives at Google during the switch and is missed. | We check the Google mailboxes for mail that arrived after the switch and bring it across, and they stay open for at least 30 days. |
A second reviewer, separate from the work that produced the plan, compares the counts, the exclusion list, the pilot note and the cut-over steps. No human supervisor is included unless your proposal names one. At launch much of the preparation is automated, and we say so.
How we deliver
We arrange the work and independent review, then show you the result against the agreed checks. You keep authority over your systems.
- Inventory mailboxes, aliases, groups, filters and the domain's mail records, and agree any folders or labels to leave out
- Confirm the prerequisites Microsoft documents: provisioned users, the mail-routing subdomains and the administrator approvals, and that the migration will be started from Exchange Online PowerShell
- Run one pilot mailbox, compare its folder counts with the Google mailbox, locate a sample of messages that carried more than one label (and any that carried a left-out label alongside a kept one), record how they arrived and agree with you what to do about any duplicates: accept them, leave a label out, or a separately quoted tidy-up
- Run the remaining mailboxes, then sync again as close to the switch as the batch allows
- The domain holder switches MX records; we test incoming, outgoing and old-folder access for each mailbox
- Check the Google mailboxes for mail that arrived after the switch and bring it across; they stay open for at least 30 days
- After sign-off, remove the migration access: delete the service-account key, revoke its delegation entry and remove the migration endpoint, and remove the routing subdomains if you agree
- Hand over the comparison and a list of anything that did not move
This is a one-off job, not emergency cover or a subscription. We confirm eligibility, the total price, a start window and a delivery date before you accept. Work starts only after agreed inputs, secure access, any licences and necessary permissions are in place. Hosting, platform and supplier charges are excluded unless the written quote includes them. No charge or booking is created by an enquiry.
Need to keep it working?
After the move, ask about the standing responsibility that keeps your mail records and authentication checked each month.
Ongoing work is separately scoped and quoted: no monitoring, response-time guarantee or automatic subscription is included in this job.
Explore an ongoing engineering lane, or mention the responsibility you need in your enquiry.
What you can check
This is a new service. We have not delivered this job for a client yet.
Other ways to get this done
- Microsoft documents a Google Workspace migration you can run yourself in the Exchange admin centre. It is a reasonable choice for an administrator who has done one before and has time to check the counts. learn.microsoft.com
- For a single person with a small mailbox, an IMAP copy from their mail app can be enough, but it moves mail only and needs checking for duplicates.
Questions
What happens to my Gmail labels?
Microsoft does not document how Gmail labels become folders or how a message with several labels is copied. We copy one pilot mailbox first and record what arrives. If the same message shows up in more than one folder, you choose: accept it, leave a label out of the copy, or ask for a separately quoted tidy-up. We then locate a sample of messages in every mailbox.
Will mail be lost during the switch?
We sync as close to the switch as possible, check the Google mailboxes for mail that arrived after it and bring that across, and keep them open for at least 30 days. No cut-over can promise zero delay for every sender, so we check mail in both directions.
Can you move my calendar and contacts too?
Not in this fixed price, but Microsoft's migration can include them. Ask for a quote that does.
Send an enquiry
Send us
- The domain, the names of the mailboxes to move and each mailbox's approximate size
- Whether staff rely on labels for their work, and how they use them
- Whether the Microsoft 365 tenant and user mailboxes already exist
- The date you need the move done by
Later, once you agree
- Administrator access at each provider arranged through a secure handoff agreed with you before any access, scoped to the migration and including permission to run the migration from Exchange Online PowerShell, or administrators who will approve each step
- The domain holder's agreement to create the routing subdomains and make the final MX change
- No live passwords, mailbox contents or customer messages by ordinary email
Both provider accounts and the domain stay in your name. Microsoft's migration tool copies mail between the two accounts; we keep no copy of your messages after sign-off, and the access you approved is removed when the job ends. The mail in the Google mailboxes is left in place.
Email fallback: open your mail app
If website submission is unavailable, review and send the fallback email yourself. An email fallback is not a website receipt. Or write to hello@syntheticindustry.ai with “email-google-workspace-to-microsoft-365-mailboxes” as the subject.