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Google Workspace Migration for Microsoft Exchange

Below are common questions about setting up and running a migration with Google Workspace Migration for Microsoft Exchange (GWMME).

Technical considerations

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Can I run GWMME on an Exchange server?

No. Microsoft doesn't support installing Microsoft Outlook on an Exchange server. It’s strongly recommended that you run GWMME on a separate client machine.

Does GWMME work in a hosted Exchange environment?

Yes, but administrator access is required, and the profile is created differently. 

GWMME accesses Exchange mailboxes using an administrator profile. If you configure GWMME using the regular Exchange options, it uses the server hostname or user options to create a profile. 

With hosted Exchange environments, direct MAPI access from Outlook to Exchange isn't possible, and you need to set up the administrator profile. For details, go to Outlook profile.

Can I run multiple instances of GWMME?

It depends on your setup:

  • You can run multiple instances on multiple client machines–If you use multiple client machines, you don’t need separate admin accounts or service accounts for each instance. However, it's important to ensure that each instance references a unique list of users. For more information, go to "Deployment scenarios" in Chapter 4 of the GWMME Admin Guide.
  • You cannot run multiple instances on a single client machine–There's a single location for configuration files. If you try to run multiple instances of GWMME on a single client, the instances overwrite each other's configuration files.
  • (Not recommended) You can run multiple instances on separate virtual machines on a single client machine—This approach can cause a high system-resource load. Instead, run one instance of the client and increase the number of users that are processed simultaneously. For details, go to "Step 3: Select the data to migrate" in Chapter 6 of the GWMME Admin Guide.
Can GWMME work with a proxy?

GWMME follows the proxy configuration defined in Microsoft Internet Explorer and uses those settings for all network connections to Google. GWMME doesn't support authenticated proxies.

Although GWMME supports proxy connections, you might need to turn on a direct connection to make sure the proxy server doesn't cause issues. The proxy configuration depends on your local setup, and Google support cannot help with this configuration. Contact your network administrator if you encounter proxy issues.

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Can multiple instances of GWMME reference the same list of users?

No. Each instance has to reference a unique list of users. If you reference the same list of users, you might have migration or API issues.

Do my MX records need to point to Google Workspace before I run GWMME?

No. You don't need to change your Mail Exchange (MX) records. You can also use a third-party gateway for email delivery. For more information, visit Manage MX records.

Does the CSV file of users to migrate need any special formatting?

Yes. For details, go to Create CSV files for your migration.

Can I schedule when the migration runs?

Yes. Use the command-line version of GWMME and run it as a Windows scheduled task. For details, go to Migrate data using the command line.

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Does running a migration affect my users?

During a migration, your users can continue to use their source account. After a migration, users will access their email, calendar, and contact data in Google Workspace rather than in their source account.

Can I use GWMME & GWMMO to migrate data?

Yes. GWMME is designed for administrators to migrate data for multiple users from an Exchange server, IMAP-compatible server, or PST files to Google Workspace. It's implemented from the server side. Google Workspace Migration for Microsoft Outlook (GWMMO) migrates data from Outlook profiles or PST files for a single user and is implemented from the client side. However, if you migrate data from both the server side and the client side, users could see duplicated data.

Can I migrate from multiple sources to one user account at a time?

No. GWMME is designed to allow only one migration at a time to a specific user.

We don't recommend having multiple concurrent API requests migrating data into a single account.

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Can I continue to use Outlook as a client for Gmail after I migrate from Exchange?

We recommend using Gmail for the best user experience. However, Google Workspace Sync for Microsoft Outlook (GWSMO) is available for users who want to continue using Outlook. GWSMO requires some setup before use. For details, visit Synchronize Google Workspace with Outlook.

After a migration, can I stop using my Exchange server?

Yes. After you migrate your data and set up your mail flow to Google Workspace, you can stop using your Exchange server.

Can I use GWMME to continually sync data between Exchange and Google Workspace?

No. GWMME is designed to migrate data from Exchange to Google Workspace. It isn't designed for data synchronization.

Do users get details about the messages that didn't migrate?

No, but administrators can. For details, go to Viewing migration reports in Chapter 8 of the GWMME Admin Guide.

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Email & calendar data

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Can I migrate folders that are nested under a system folder?

Yes you can, but they appear a little differently in Gmail after a migration. Gmail doesn’t allow you to nest a label under a system label (such as, Inbox, Sent, or Trash). If you migrate a folder that is nested under a system folder, GWMME creates a Gmail label to match the system folder but prefixes it with an underscore character.

For example, if you have a Projects folder under the Sent folder in your source mail server, GWMME creates a _Sent label and nests the Projects label underneath it in Gmail.

Does GWMME migrate calendar resources and shared calendars?

You can migrate calendar resources from Exchange, but you need to create them in Google Workspace first. Then, use GWMME to migrate events to the calendar resource.

You can also migrate shared calendars. However, only the owner retains access to the calendar after a migration. Calendars in a public folder are not migrated.

If I move a message from one Exchange folder to another and then run a migration, does the message get migrated twice?

If you choose the Migrate all data option, the message is migrated twice. On the second migration, a new Gmail label is applied (which matches its new Exchange folder).

Should I use a different migration option if I'd like to keep using Outlook?

You can let users migrate their email, calendar, and contact data from an Exchange account or local PST file into a Google Workspace account using Google Workspace Migration for Microsoft Outlook (GWMMO).

To keep using Outlook, Google Workspace Sync for Microsoft Outlook (GWSMO) lets users synchronize mail, calendar events, contacts, notes, and tasks between Outlook and a Google Workspace account.

For more migration options, go to the Google Workspace migration product matrix.

If we have years of email in an on-site archive, can it be migrated to Google Workspace?

Yes, but the archived messages must be moved to Exchange or PST files first and then migrated.

Can I migrate messages to an archive?

Yes. You can migrate all messages (or a selected period) to Google Vault. You can migrate to Vault from PST files or any supported mail server, including Exchange, IMAP, and Gmail. Migrated messages are not visible in users' Gmail inboxes. For details, go to Step 3: Select the data to migrate in Chapter 6 of the GWMME Admin Guide.

Can I estimate the number of messages without doing a migration?

Yes. You can have GWMME scan to estimate the number of items to migrate. For details, go to Step 4: Migration settings in Chapter 6 of the GWMME Admin Guide

Why is there a difference between the number of messages in the source account and the number migrated to Gmail?

This discrepancy might be due to the difference between folders in Exchange and IMAP mail servers and labels in Gmail. In Exchange and on IMAP mail servers, when you assign a message to more than one folder, the message is duplicated. Following a migration, the duplications are removed in Gmail and different labels are applied instead.

To verify all messages have been migrated, check the logs for errors. For details, go to Chapter 7: Migration reports in the GWMME Admin Guide.

If you think you're missing some messages, check the troubleshooting steps in The number of Gmail messages doesn't match my source account.

Can I sync email between Google Workspace and my on-premises Exchange Server?

No, but your users can set up dual delivery so messages are sent to Google Workspace and Exchange. For details, visit Deliver email to multiple inboxes with dual delivery.

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Related topics

Google, Google Workspace, and related marks and logos are trademarks of Google LLC. All other company and product names are trademarks of the companies with which they are associated.

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