AppBridge Documentation : Review features and watch points - Microsoft Exchange to G Suite Migration

In the review phase of a Microsoft Exchange to G Suite (formerly Google Apps) migration using Transformer, you will:

Supported Features


FeatureTarget ObjectSupportedWatch Points
Copy User MailboxUser MailboxYes 
Copy Group Mailbox
  • Group Mailbox
  • User Mailbox
Copy Shared (delegated) Mailbox
  • Group Mailbox
  • User Mailbox
Copy MailMailYesThroughput - Email. Invalid data header issue - Email.
Copy Mail - Read StateMail - Read StateYes 
Copy Mail - PriorityGmail ImportanceYes 
Copy FoldersLabelsYesSystem sub-labels will be reorganized.
Copy Folder HierarchyLabel HierarchyYesSystem sub-labels will be reorganized.
Copy Mail CategoryLabelsYesOnly categories in use will be migrated.
Copy Mail Attachments
  • Mail Attachments
  • Google Drive Files (link embedded in Mail)
YesLarge attachments will be added to Google Drive.
Copy DraftsDraftsYes 
Copy TrashTrashYes 
Copy SpamSpamYes 
Copy Mailbox ArchiveGoogle VaultComing Soon 
Copy CalendarsCalendar - PrimaryYes 
Copy Calendars - Secondary Calendar - Secondary Yes 
Copy Calendar EventsCalendar EventsYes 
Copy Calendar Events - RecurringCalendar Events - RecurringYes 
Copy Calendar Attachments

Google Drive Files (link embedded in Calendar event)

YesAll attendees on the event are granted access to the file in Google Drive.
Copy Calendar Events - ExternalCalendar Events - ExternalYes 
Calendar Event attendee responsesCalendar Event attendee responsesYesResponses can optionally be disabled to improve migration performance.
Calendar PermissionsGoogle SharingYesUsers will receive emails indicating that Calendars have been shared with them during migration. It is possible to configure a content compliance rule to ensure that these emails are filtered.
Calendar Notes
  • Reminders
  • All day appointments
Calendar RemindersRemindersYesReminders can be migrated as Google Calendar reminders.
Public Folders   
Copy Public Folders Google Group MailboxYes 
Copy ContactsContactsYes 
Copy Address BooksContact GroupsYes 
Distribution GroupsGoogle GroupsNo 
Google Tasks TasksYesTask sub-folders are migrated to separate task lists.
Rooms and Equipment 
Copy Meeting Rooms and Equipment Calendar EventsGoogle Resources Calendar EventsYesMigrating to Google resource calendars.
Settings - FiltersGmail Settings - FiltersYesNot all Exchange rules and actions have Google equivalents.
Settings - SignaturesGmail Settings - SignaturesYes 
Settings - Vacation ResponderGmail Settings - Vacation ResponderYes 
Settings - ForwardingSettings - ForwardingYesSetting up a forwarding address can prompt a message to the recipient of the messages.
Settings - Send AsSettings - Send AsYes 

Watch Points

Watch pointDescriptionBest Practice
Throughput - EmailTo avoid duplication and errors, Emails being written to the target domain must be analyzed. Emails that have been forwarded or migrated to the target environment prior to the production migration may create issues for Transformer.

Transformer provides the ability to significantly increase the speed of migration by using the Accelerate Old Messages setting for Gmail migration.

If email forwarding is used, the Insert Before Date field should be set to the day before forwarding was turned on.

Invalid data header issue - Email

We have discovered a problem that occurs when source emails have invalid headers for their Dates. These emails may appear as having arrived at a specific time on the source system, but the data for the email itself does not accurately include the delivery time. In this case, the messages will appear in the target mailbox as having arrived at migration time.

The issue is caused by emails that have Date headers that don't conform to the RFC 2822 standard for emails.

AppBridge is currently investigating options for dealing with this issue. We have found that it can occur on multiple types of email servers.

System sub-labels


In Gmail, system labels cannot have sub-labels. Exchange supports sub-folders under all folders. Therefore, some folders from Exchange may need to be reorganized. Essentially, the sub-folders will be created outside of the system labels. Both the system label and the new custom label will be applied.Communicate this change to end-users in advance.
Large attachmentsBy default, all attachments over 25MB will be added to Google Drive. In the body of the email, a link to the attachment replaces the file. The size threshold and destination folder name are configurable. 
Resource calendars

When migrating Exchange Meeting Rooms, Transformer supports updating resource calendars in the target Google environment based on events. This works a little different than the G Suite to G Suite case.

For G Suite to G Suite, we migrate the calendar for the resource itself. Due to source API limitations, we cannot use that approach for Exchange. Instead, we create events on the resource calendars when we migrate the event for the organizer.

For that flow, you should map the room or equipment email in Exchange to the email for a Resource in the Google environment. When we migrate the calendar of the organizer of an event that uses that room or equipment, we will map the attendee email to the Google Resource email. We will then write the event to the Resource calendar explicitly.

Filters that don't have Google equivalents.
The following actions and conditions do not have an equivalent mapping in Gmail.
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
Link correction - non Google-native filesLink correction within non Google-native files is not supported.

Transformer maintains a link correction dictionary for all objects migrated, which can be exported from the software. This dictionary can be used post-migration to identify and repair broken links.

AppBridge will be releasing a limited non Google-native file link correction feature in an upcoming build. Please contact if you have any questions about this feature.


Next: Preparation - Microsoft Exchange to G Suite Migration