Calendar and Contacts Migration: Google to Outlook¶

Status: Authored 2026-04-30 Audience: M365 administrators and migration engineers handling Google Calendar and Contacts migration to Exchange Online / Outlook. Scope: Calendar event migration, recurring event handling, room/resource migration, contact migration, delegation, and Google Calendar interop considerations.

Overview¶

Calendar and contact migration is typically handled alongside email migration using the Google Workspace migration feature in Exchange Admin Center (EAC). When configured for Google Workspace migration, the migration batch migrates email, calendar events, and contacts in a single pass.

Key consideration: Calendar migration is time-sensitive. Migrating calendar data early gives users their schedules in Outlook before the email cutover, reducing day-one confusion.

Calendar migration methods¶

Recommendation¶

Use the Google Workspace migration in EAC for calendar and contacts. It is included in the email migration batch and provides the best fidelity for calendar events, recurring patterns, and attendee lists.

Calendar event migration¶

What migrates¶

What does not migrate¶

Recurring event pattern mapping¶

Room and resource migration¶

Google Workspace room resources¶

Google Workspace manages room resources through the Admin Console. These do not migrate automatically and must be recreated in Exchange Online.

Step 1: Export Google room resources¶

In Google Admin Console, navigate to Directory > Buildings and resources > Resources. Export the resource list including:

• Resource name
• Resource email (e.g., boardroom@resource.contoso.com)
• Building
• Capacity
• Features (video conferencing, whiteboard, phone)

Step 2: Create room mailboxes in Exchange Online¶

# Connect to Exchange Online
Connect-ExchangeOnline -UserPrincipalName admin@contoso.com

# Create room mailboxes
New-Mailbox -Name "Board Room" `
    -Room `
    -PrimarySmtpAddress "boardroom@contoso.com" `
    -ResourceCapacity 20

New-Mailbox -Name "Conference Room A" `
    -Room `
    -PrimarySmtpAddress "confroomA@contoso.com" `
    -ResourceCapacity 10

# Configure room booking policies
Set-CalendarProcessing -Identity "boardroom@contoso.com" `
    -AutomateProcessing AutoAccept `
    -AllowConflicts $false `
    -BookingWindowInDays 180 `
    -MaximumDurationInMinutes 480

# Add room features
Set-Place -Identity "boardroom@contoso.com" `
    -IsWheelChairAccessible $true `
    -AudioDeviceName "Poly Studio" `
    -VideoDeviceName "Surface Hub" `
    -DisplayDeviceName "85-inch display" `
    -Building "HQ" `
    -Floor 3 `
    -Capacity 20

Step 3: Create room lists¶

# Create room lists (room finders in Outlook)
New-DistributionGroup -Name "HQ Rooms" `
    -RoomList `
    -PrimarySmtpAddress "hqrooms@contoso.com"

# Add rooms to the list
Add-DistributionGroupMember -Identity "hqrooms@contoso.com" `
    -Member "boardroom@contoso.com"
Add-DistributionGroupMember -Identity "hqrooms@contoso.com" `
    -Member "confroomA@contoso.com"

Step 4: Configure room booking delegates (if applicable)¶

# Set room delegates (for rooms requiring approval)
Set-CalendarProcessing -Identity "boardroom@contoso.com" `
    -AutomateProcessing AutoAccept `
    -ResourceDelegates "admin@contoso.com","receptionist@contoso.com" `
    -AllBookInPolicy $false `
    -AllRequestInPolicy $true

Equipment resources¶

Google Workspace equipment resources (projectors, vehicles, etc.) map to Exchange Online equipment mailboxes:

# Create equipment mailbox
New-Mailbox -Name "Projector 1" `
    -Equipment `
    -PrimarySmtpAddress "projector1@contoso.com"

Set-CalendarProcessing -Identity "projector1@contoso.com" `
    -AutomateProcessing AutoAccept

Contact migration¶

Personal contacts¶

Personal contacts in Google Contacts migrate automatically with the Google Workspace migration in EAC. The migration maps:

Shared contacts (directory)¶

Google Workspace shared contacts (domain contacts visible to all users) map to Exchange Online contacts:

# Create mail contacts for external shared contacts
New-MailContact -Name "Partner Contact" `
    -ExternalEmailAddress "partner@external.com" `
    -FirstName "Jane" `
    -LastName "Smith"

# Create org-wide contacts visible in GAL
# Contacts created as MailContact appear in the Global Address List

Google Directory (GAL equivalent)¶

The Google Workspace directory (all users) automatically populates the Exchange Online Global Address List (GAL) when users are provisioned in Entra ID. No manual migration is needed for internal directory entries.

Calendar delegation migration¶

Google Calendar delegation types¶

Configure calendar delegation¶

# Grant calendar reviewer permission (view all details)
Add-MailboxFolderPermission -Identity "user@contoso.com:\Calendar" `
    -User "assistant@contoso.com" `
    -AccessRights Reviewer

# Grant calendar editor permission (make changes)
Add-MailboxFolderPermission -Identity "user@contoso.com:\Calendar" `
    -User "assistant@contoso.com" `
    -AccessRights Editor

# Grant delegate permission (full access + send on behalf)
Add-MailboxFolderPermission -Identity "user@contoso.com:\Calendar" `
    -User "assistant@contoso.com" `
    -AccessRights Editor

Set-Mailbox -Identity "user@contoso.com" `
    -GrantSendOnBehalfTo "assistant@contoso.com"

Post-migration validation¶

Calendar validation checklist¶

• Single events appear with correct dates, times, and attendees.
• Recurring events show correct patterns (daily, weekly, monthly).
• Recurring event exceptions are preserved.
• Room bookings appear on room calendars.
• All-day events display correctly.
• Event attachments are accessible.
• Calendar delegation works (delegates can view/edit as configured).
• Free/busy information is visible to other users.
• Time zones are correct for all events.

Contact validation checklist¶

• Personal contacts are visible in Outlook People.
• Contact details (phone, email, address) are complete.
• Contact photos are displayed.
• Contact groups are preserved.
• Global Address List shows all internal users.
• External shared contacts are visible in GAL.

Coexistence considerations¶

During the migration period, some users will be on Google Calendar and others on Outlook Calendar. To maintain scheduling capability:

Free/busy interop¶

Free/busy interop between Google Calendar and Outlook Calendar is not natively supported. During the coexistence period:

1. Migrate by team/department to minimize cross-platform scheduling.
2. Fast-track calendar migration --- run calendar migration before email cutover so all calendars are in Outlook even if email is still in Gmail.
3. Communication: Tell users that scheduling across platforms during coexistence requires manual coordination.

Google Meet links in migrated events¶

After migration, existing events with Google Meet links will still show the Meet link. These links will continue to work as long as Google Workspace licenses are active. After Google Workspace decommission, Meet links become non-functional.

Recommendation: After migration, have users add Teams meeting links to future events and communicate that Google Meet links on historical events will stop working after decommission.

Troubleshooting¶