Migrate from OVH to Google Workspace: The Zero-Downtime Method

Moving from OVHcloud email plans — Email Pro, Exchange or Zimbra (MX Plan) — to Google Workspace means bringing Gmail, Drive, Calendar and Meet together in a single environment. The worry is always the same: losing years of history, or cutting off mail in the middle of the day. Good news: with the right method and a proper migration tool, the switch happens with no data loss and no visible interruption for the people who write to you.

What gets migrated — and why leave OVH

An email migration covers far more than the messages themselves. You need to plan for everything attached to the accounts:

• Email: inbox, folders, sent items, drafts and archives, with their full folder tree.
• Contacts: each user's personal address book and any shared lists.
• Calendars: appointments, recurring meetings and shared calendars.
• Files: documents stored on an OVH space (web hosting, NAS) that you want to move to Google Drive.

The reasons are familiar: bring mail and productivity into a single license, benefit from Gmail search and the real-time collaboration of Docs and Sheets, get larger mailboxes, and centralize administration. Moving from Email Pro or Zimbra to Google Workspace also simplifies day-to-day life for teams.

Step 1 — Audit and inventory before touching DNS

No successful migration starts with the technical part. It starts with a precise inventory:

• List every mailbox to migrate (named accounts, generic ones like contact@, aliases, forwards).
• Measure the volume of each mailbox: it drives how long the transfer takes and the risk of rate limiting.
• Identify your exact OVH plan (Email Pro, Exchange or Zimbra MX Plan): the IMAP server and connection settings depend on it.
• Check the domain and DNS: note who manages the zone, the current MX records, the SPF, the DKIM and above all the TTL. Lower the MX TTL (for example to 300 seconds) a few days before the cutover so the change propagates quickly.

Step 2 — Provision Google Workspace

On the target side, subscribe to Google Workspace, add and verify your domain in the Admin console (Google provides a TXT validation record), then create the users and assign licenses. At this point, do not change the MX yet: the new Gmail mailboxes are ready but empty, and mail keeps arriving on OVH. This lets you prepare the transfer with complete peace of mind.

Step 3 — Migrate email with the Data Migration Service

Because OVH plans expose IMAP, the reference method is Google Workspace's Data Migration Service (DMS) in the Admin console:

• Choose the "Other IMAP server" source, then enter the OVH server (for example ssl0.ovh.net) on port 993 over SSL.
• Provide a mapping file that links each source address to the target Google mailbox, with the required credentials.
• Start the migration: Google copies email in the background, without touching the incoming mail that stays on OVH.

For small volumes, an MBOX export through a client like Thunderbird, then import, is a simple alternative. Keep in mind that the DMS transfers email and, depending on the source, calendars and contacts — but a generic IMAP source only carries mail, so contacts and calendars are then handled separately.

The secret to a zero-downtime switch: copy everything while the old mail system is still running, and only change the MX once the copy is finished.

Step 4 — Contacts, calendars and files

Contacts and calendars don't always follow IMAP. The most reliable approach is to export contacts as CSV/vCard and calendars as .ics from the old OVH webmail, then import them into Google Contacts and Google Calendar. For files, move documents to Google Drive: install Google Drive for desktop, copy folders into a shared drive for team data, and let synchronization finish the upload in the background.

Step 5 — Cut over DNS/MX with no downtime

Once the initial copy is done, change the DNS records at OVH (or your registrar) to point to Google:

• MX to the Google servers (ASPMX.L.GOOGLE.COM and the associated backup entries).
• SPF updated with include:_spf.google.com, then DKIM enabled from the Google Admin console.
• Add a DMARC record to protect your domain.

Thanks to the lowered TTL, propagation is fast. During a few hours of coexistence, some mail may still land on OVH; run a delta sync (another DMS pass) to pull in messages received between the initial copy and the cutover.

Step 6 — Verification and client settings

Check that no folder is missing, send and receive a test email, then reconfigure access: in the browser, Gmail works immediately; on Outlook, reconfigure the account with Gmail IMAP or Google Workspace Sync; on mobile, remove the old OVH account and add the Google account. Also check signatures, filters and forwards.

Common pitfalls

• Rate limits: OVH and Google cap simultaneous IMAP connections. Spread out the batches to avoid transfer errors.
• Duplicates: don't rerun a full migration after the cutover — only a delta sync — or you'll duplicate messages.
• Gmail labels: Gmail organizes mail by labels rather than folders; check the mapping after import.
• Recurring calendars: some recurring meetings or invitations can shift; check them after importing the .ics file.
• Cancelling OVH too early: only close the source plan after several days of confirmed operation on Google Workspace.

How much it costs: Yuna7 vs an IT contractor

Having a contractor migrate OVHcloud to Google Workspace often costs several hundred dollars, with quotes and lead times. Yuna7 automates the switch and you only pay for what's actually used — you can even try it free.

Let Yuna7 migrate OVHcloud to Google Workspace for you

Describe your migration in one sentence — "migrate my OVH mailboxes to Google Workspace" — and the AI does the rest: it audits the mailboxes and DNS, provisions the users, transfers email, contacts, calendars and files through the Data Migration Service and Google Drive, cuts the MX over at the right moment and verifies nothing is missing. You only approve the sensitive steps. Far cheaper than a technician, and launched in minutes.