Monitoring points for Exchange

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

Email forwarding
To avoid duplicates and errors, email messages are checked to make sure they don’t already exist in the target mailbox. If you use email forwarding and enable the Accelerate old messages setting, 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.
Deleted email messages
Deleted messages go to Trash in Gmail. Per Gmail guidelines, items in Trash are deleted after 30 days. For details, go to Delete or recover deleted Gmail messages.
Large attachments
During a migration, email attachments over 25 MB are added to Google Drive. A link to the attachment is added to the migrated message. 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.
Date headers in email
If an email has a date header that doesn't conform to the RFC-2822 standard, you will see the migration date, not the original message date, in the target mailbox.
Difference in the total amount of email messages
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.
Migrating messages to Google Groups
When viewed in Groups, migrated email messages appear as read by the user who sent them. For other group members, the messages appear as unread.
Links in email messages
Gmail scans migrated email messages for security and threat issues and occasionally crawls links in the body of email messages. To avoid this issue and modestly increase migration performance, you can use the Accelerate old messages option in your settings template. Before you do, review how it works. For details, go to Migrate Exchange content.
Email messages sent by users to themselves
If Exchange users sent a message to themselves and the message is in the Sent folder, following a migration: 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

Migrating folders to 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 Spam and 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 -migrated appended 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.
Folder names that contain special characters or multiple sequential spaces
After a migration, folder names that contain the following characters or spaces don’t directly match label names on the target account: 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.
Label colors
Only standard label colors are supported. Any non-standard colors for categories on the source account don't migrate as labels. 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

Exchange email filters

The following actions and conditions don’t have an equivalent in Gmail, and they're ignored during a migration: 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

API limits
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.
Primary to secondary calendar migration
To map a primary calendar to a secondary calendar on your target domain, use a GCalendar entry in your mapping. 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, [e-mail]). The Google 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.
Use an identity mapping
Use an identity mapping to: 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

Steps to migrate resources & event associations
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.
Auto-accepted meetings
If the calendar resource is set to Auto-accept meetings that do not conflict (the default) and conflicting bookings are migrated, the meeting organizer gets an email for each declined invitation. The super administrator account used to migrate the resource also receives an email. For details on using super admin accounts to migrate calendar resource events, go to Migrate using super administrator accounts.  To use content compliance rules to deliver these messages to email quarantines, go to Set up rules for advanced email content filtering.
Migrate using super administrator accounts
By default, Google Workspace Migrate uses all super administrator accounts to write calendar resource events to the target domain. Using super admin accounts increases migration speed and reduces the risk of quota issues. 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 events setting in the Exchange settings template, only the Google Workspace Migrate admin account is used to migrate calendar resources.
Resources created after January 21, 2020
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

Groups
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.
Exchange contact notes
Unlike Google Workspace, there is no limit to the notes size for an Exchange contact. When contact notes are migrated, large notes might be truncated in Google Workspace.
Migrating large numbers of contacts
Google Contacts supports up to 25,000 personal contacts for each user. Before you migrate, make sure your users have fewer than 25,000 personal contacts in Exchange.
Tasks
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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