What do you need before an Exchange migration starts?
Before an Exchange migration starts, you need a full mailbox inventory, an admin account that can read every mailbox, and a server the migration tool can reach. Missing any of these is the most common reason a migration stalls on day one.
Gather this during discovery:
- Every mailbox, including shared mailboxes, room and equipment mailboxes, and accounts for people who have left.
- Mailbox sizes, so the largest ones can start copying first.
- Aliases, distribution lists, and forwarding rules.
- Public folders, if you use them.
- PST archives saved on desktops or file shares.
- Who manages your DNS, and how to sign in to it.
Also check the health of the server. An Exchange server with full disks, expired certificates, or missing updates will copy slowly or fail partway through. Fix those problems first. This guide is part of our larger email migration guide, which compares Exchange with other platforms.
How do you set up Google Workspace for an Exchange move?
You set up Google Workspace by verifying your domain, creating a user for each mailbox, and recreating groups before any mail moves. Users can be added one at a time in the Admin console or in bulk with a CSV upload. Shared mailboxes and distribution lists usually become Google Groups, which our guide to shared mailboxes and distribution lists covers.
Do not change your MX records yet. At this stage your domain is verified in Google Workspace, but mail still flows to Exchange and people keep working normally.
How is Exchange data copied to Google Workspace?
Exchange data is copied by a migration tool that signs in to the server with admin rights, reads each mailbox, and writes mail, calendar events, and contacts into the matching Google Workspace account. Google offers its own migration options, and third-party tools exist as well. The right choice depends on the size of the move and which data you need.
A few practical points:
- Start with a pilot group of a few users. Check their folders, calendar invites, and contacts in Google Workspace before copying everyone.
- Outlook folders become Gmail labels, and nested folders become nested labels.
- Recurring meetings and room bookings deserve a careful check, because that is where calendar data most often looks different after a move.
- Large mailboxes take the longest. Start them early so the copy is finished well before switchover.
If your team keeps old mail in Outlook archive files, those need a separate step. Our guide to migrating PST archives into Gmail explains it, and our guide to moving Exchange public folders covers shared folders.
What happens on switchover day?
On switchover day, you change your MX records to point at Google, wait for the change to spread, then run a final delta sync to copy anything that arrived during the switch. Our MX record cutover guide explains the DNS side, and our explainer on what a delta migration is covers the final sync.
While DNS updates, some mail may still arrive at Exchange for a short time. That is normal, and the delta sync picks it up. It is also why the old server must stay online after the switch.
Once mail is flowing to Gmail, help people sign in on their computers and phones. If some users want to keep Outlook on Windows, Google Workspace Sync for Microsoft Outlook connects it to their new account.
When can you turn off the Exchange server?
You can turn off the Exchange server once the final sync is complete, no mail is arriving there, and every user has confirmed their data is in Google Workspace. Do not rush it. Keep the server running, or at least keep a full backup, until you are sure nothing was missed.
Before you retire it, check these:
- Scanners, printers, and business apps that sent mail through Exchange now send through Google or another relay.
- Your SPF, DKIM, and DMARC records are updated for Google. See our guide to SPF, DKIM, and DMARC.
- Any legal or retention requirements for the old data are met.
Next step
If you are planning an Exchange move, tell us about your server and mailbox count on our Exchange migration page, and we will map out the switchover with you.
Frequently asked questions
Can we migrate from Exchange if our server is old?
Usually, yes, but older servers need more preparation. Migration tools must connect securely, so outdated certificates, protocols, or unpatched systems can block or slow the copy. Test a pilot mailbox early so problems surface before the real schedule starts.
Do existing calendar events survive the move from Exchange?
Existing events copy across with their details and attendees. After the switch, people reply to and schedule meetings in Google Calendar. Recurring meetings and room bookings are worth checking in a pilot, because that is where differences most often appear.
Will archived PST files move with each mailbox?
No. PST files sit on desktops or file shares, not on the Exchange server, so mailbox migration tools do not see them. They need to be found, checked, and imported as a separate step in the plan.
