Migrate from Zimbra to Google Workspace: The Guide

Zimbra powered SMBs and hosting providers for years, but many organisations now prefer Google Workspace for Gmail, Calendar, Drive and real-time collaboration. The good news: moving from Zimbra to Google Workspace happens without losing mail and without downtime, as long as you follow the right order. This guide walks through each stage, from the audit to the final checks.

What gets migrated, and why people switch

A Zimbra mailbox holds far more than email. Plan the transfer of:

• Emails and their folder tree, along with read/unread status flags.
• Contacts, both personal and shared address books.
• Calendars and their recurring events.
• Files from the Zimbra Briefcase, to move into Google Drive.

Organisations usually move to Google Workspace for Gmail, co-editing in Docs/Sheets, Meet, and to be free of maintaining a self-hosted mail server.

Preparation: audit first

Start with a full inventory of the Zimbra accounts: the list of mailboxes, the size of each, aliases, distribution lists and resource accounts. Confirm that IMAP access is enabled on Zimbra, because that is the channel Google will use to copy the data.

• Note who owns the domain and who has access to the DNS zone.
• Record the existing MX, SPF, DKIM and DMARC records.
• Lower the TTL on the MX records (for example 300 s) a few days before cutover.

Provision Google Workspace

Create the Google Workspace subscription, add your domain and verify it using the TXT record provided in the Google Admin console. Then create each user (same addresses as on Zimbra), groups and aliases. As with any clean migration, do not touch the MX yet: mail keeps arriving on Zimbra during the copy.

Migrate email with the Data Migration Service

For email, the native, free route is the Google Admin console's Data Migration Service (DMS). It connects to the Zimbra mailboxes over IMAP and copies messages, folder by folder, without interrupting service. You provide the Zimbra IMAP server address and credentials, then run the migration in batches of users.

• DMS handles email; contacts and calendars are handled separately.
• As an alternative for small volumes, you can export to MBOX from Zimbra and re-import, but DMS remains the recommended method.

Contacts, calendars and files

Export contacts from Zimbra as CSV and import them into Google Contacts. Export calendars as ICS and import them into Google Calendar; check recurring events and time zones. For the Zimbra Briefcase files, download them and upload them into Google Drive, reorganising sharing to match your teams.

Cut over DNS/MX with no downtime

Once the initial copy is complete, change the MX records to point to Google's servers (for example ASPMX.L.GOOGLE.COM and its backups). Publish Google's SPF record, enable DKIM from the Admin console, and adjust DMARC if needed. The lowered TTL makes propagation near-instant. Finish with a delta pass to pull in messages that reached Zimbra during the cutover.

Migrating with no downtime means letting the old server receive until the very last minute, then catching the difference: no message falls between the two.

Verification and client settings

Set up the clients on the new Google Workspace accounts (Gmail web, mobile app, or Outlook over IMAP if needed). Check sending and receiving, signatures and filter rules. Send an external test message to confirm SPF and DKIM validate, and that replies land back in Gmail.

Common pitfalls

• IMAP rate limits on Zimbra: split large accounts into several batches.
• Duplicates if a migration is re-run without purging first.
• Nested folders or special labels not carried over: check the folder tree after copy.
• Recurring calendars shifted by time zones.
• Forgetting the delta pass and losing mail received during the cutover window.

How much it costs: Yuna7 vs an IT contractor

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

Let Yuna7 migrate Zimbra to Google Workspace for you

Describe your migration in one sentence: Yuna7 audits your Zimbra mailboxes, provisions Google Workspace, runs the Data Migration Service, transfers contacts, calendars and files, cuts over the DNS/MX, then verifies each account — you only approve the sensitive steps. It all runs on your machines, under your control, and for far less than a technician.