If you haven’t yet, review the Google Workspace Migrate best practices first .
Before you migrate content from Microsoft Exchange, review the following points for email, calendar resources, and other data.
Email messages | Gmail labels | Email filters | Calendar data | Calendar resources | Other types of data
Email messages
If you use email forwarding and enable the Accelerate old messagessetting, set the Insert Before Date field to the day before forwarding was turned on to reduce the risk of data duplication. For details, go to Migrate Exchange content .
You can configure the size threshold and Drive folder name for these attachments in the settings template. For details, go to About Exchange settings template options .
Due to the difference between folders in Exchange and labels in Gmail, the number of email messages in the source account might exceed the number of messages migrated to Gmail.
In Exchange, 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 that all messages have been migrated, check the logs for any errors. For details, go to Monitor migration progress . To troubleshoot further, go to Missing email messages .
To avoid this issue and modestly increase migration performance, you can use the Accelerate old messagesoption in your settings template. Before you do, review how it works. For details, go to Migrate Exchange content .
- The read or unread status of the message might not be preserved.
- Messages that belong to the Spam or Trash labels might appear in All Mail, rather than Spam or Trash.
Gmail labels
Email folders and subfolders are migrated as labels and sublabels in Gmail. Gmail supports up to 5,000 labels in a user mailbox. Labels have the same name and hierarchy as folders, except as indicated below.
Note the following points:
- Make sure your users have fewer than 5,000 email folders in Exchange.
- Tell users if they have more than 500 labels, Gmail can take longer to load. After a migration, your users can create labels to organize Gmail .
- While Exchange supports subfolders under all folders, some Gmail labels (such as Spam and Trash) can't have sublabels. Google Workspace Migrate creates a new label (not sublabel) for the messages. For example, migrated email from the Spam/ subfolder folder has the Spamand subfolder labels applied.
- Due to Gmail's limits on label length (225 characters for the folder path and label), a long folder name from Exchange might be un-nested (the higher level labels are removed) or truncated and suffixed with an ellipsis (...).
- A source folder that has the same name as a Gmail system label (for example, Starred) has -migratedappended to the label.
- Outlook has nested folders under the Sync issues folder that contain Outlook-related sync logs and warnings. Following a migration, the sync issues in these messages are unrelated to the migration process. To exclude these folders, go to About Exchange settings template options .
- ISO control characters or the caret symbol (^)
- Multiple sequential spaces
- A space at the beginning or end of the folder name
On the labels created from the folders:
- Special characters are removed.
- Sequential spaces change to a single space.
- Spaces at the beginning or end of a folder name are removed.
During a migration, folders that have the same name (following any adjustments) merge into one label. For example, because special characters are removed, the folders Financial1 and Financial1^ merge under the label name Financial1 .
If you get an error, remove the custom colors from categories in the source account and try again. For details about standard label colors, go to Gmail API: Color .
Email filters
Actions
- Forward as attachment to recipient
- Permanent delete
- Send SMS alert to recipient
- Server reply with message
- Stop processing rules
Conditions
- Category
- Flagged for action
- From connected account
- Importance
- Is approval request
- Is automatic forward
- Is automatic reply
- Is encrypted
- Is meeting request
- Is meeting response
- Is non-delivery report
- Is permission controlled
- Is read receipt
- Is signed
- Is voicemail
- Item class
- Message classification
- Not sent to me
- Sensitivity
- Sent cc me
- Sent only to me
- Sent to me
- Sent to or cc me
- Within date range
Calendar data
If you're running a large migration (1,000+ calendars), you might reach the Google Calendar API daily limit and see 403 errors. You can request an increase to the query-per-minute limit for the Calendar API:
- Run a scan to get the total number of events and users that you need to migrate.
- Determine how many users you're likely to migrate at the same time.
- Request a Calendar API queries-per-minute quota of 160 times that amount. For details, go to Requesting a higher quota limit .
Your mapping should include:
- Source ExchangeUser–Email address of the owner of the primary calendar.
- Source ExchangeCalendar–The path to the primary calendar (usually /Calendar).
- Target GUser–Email address of the owner of the secondary calendar.
- Target GCalendar–Google Calendar's calendar ID (for example, example.com_xxx@group.calendar.google.com). The calendar must be created prior to the migration. You can use the Google Calendar API to create calendars.
- MapChildrenOnly–Set to True (required to map calendar events to a pre-existing calendar).
Important: If the mapping is misconfigured, events might be migrated to the target user's primary calendar. Check your mapping carefully before proceeding. For details, go to Migrate calendar to a GUser-owned secondary calendar .
- Transfer calendar resources
- Map an event organizer, when the organizer is external to your organization
For details, go to Create & manage an identity mapping .
Calendar resources
- Resources must be created manually or by bulk import in the target domain. For details, go to Create buildings, features & Calendar resources .
- Add your source and target calendar resources to the mapping. Use the following headers:
- Source ExchangeUser–Use the email address of the Exchange calendar resource.
- Target GCalendarResource–Use the email address of the Google Calendar resource.
For details, go to Create & manage a mapping .
- Map the calendar resources in an identity mapping. Go to Create & manage an identity mapping .
To use content compliance rules to deliver these messages to email quarantines, go to Set up rules for advanced email content filtering .
Note the following points:
- At least 24 hours before you run a migration, create the super admin accounts and assign privileges. For details, go to Pre-built administrator roles .
- All super admins must have the Google Calendar service turned on. Otherwise, you'll get failures in your migration. For details, go to Turn a service on or off for Google Workspace users
- Following a migration, the resource event shows as "Created by" the super admin. The activity is tracked in the Calendar audit and investigation page .
- If you turn off the Use all super admins to write resource calendar eventssetting in the Exchange settings template, only the Google Workspace Migrate admin account is used to migrate calendar resources.
Calendar resources created after January 21, 2020, might show unexpected Location Not Found errors during a migration.
To resolve these errors, upgrade to Google Workspace Migrate version 2.1.26.0 or later. For details, see Upgrade the software .
Other types of data
For Google Groups, you must create groups in the target account first. Groups aren't automatically created by the migration process.
When migrating groups:
- Use an identity mapping to map a group on the source account to an existing group on the target account. For details on what to specify in the mapping, go to Create & manage an identity mapping .
- It might take up to 24 hours to see new groups on the target account. Until then, you won't see them in the tree-view for a scoped view or mapping. Additionally, a mapping for a group could display as invalid.
- When tasks are migrated to Google Workspace, they show as an all-day task.
- Recurrence settings for tasks and deleted tasks aren't migrated.
Next step
Now it's time to set up an Exchange connection. To get started, see Set up Exchange connection .
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