There could be some situations like acquisition or divestiture when you need to enable free busy (calendar availability) sharing between office 365 and google apps, It will help your end users to have better availability visibility and help in planning their meetings without so much of email exchange.

I have seen article from Google on calendar sharing but those doesn’t provide detail with screenshot, In rest of the article i will explain how to enable free/busy sharing between Google Apps and Office 365. This calendar sharing will be setup between these domains of Office 365 and Google Apps.

  • Office 365 – and tenant domain is

  • Google Apps –

  • Create a normal account in Google Apps & Office 365, this will be used as a service account.
  • Login to Google Admin Portal

  • Navigate to Dashboard and click on ‘Apps’.


  • Click on ‘Google Suite’


  • Click on ‘Calendar’


  • Navigate to end and click on ‘Calendar Interop management’
  • Fill information like below and save changes:


  • Navigate to and login with super administrator credentials and click on Execute.execute1.JPG
  • Now login with service account of Google Apps created for free/busy.
  • Confirm that you see the name of your service account, now Click on Allow.7.apps
  • Now you will be prompted to download a .dat file,


  • Now click on second highlighted option.


  • Upload .dat file from your desktop and fill information like below and click on ‘Show Exchange Setup’ :


13.apps (2).png

  • Run below command on Office 365 exchange online powershell using Global Administrator credentials.

Exchange server configuration

Configure your Exchange server with the following settings. Note that the username and password here are specific to Exchange, and are not the username and password of the Google Role Account.

The server URL to give Exchange is:
The username to give Exchange is:\sj
The password to give Exchange is: x5LPh21NXLoYJFG-ewP1MS74QJRjCSSjV9n7l1OH4qCaINUJUfKLMkBQpmXAqPkN

You can cut-and-paste the following line of PowerShell code directly into the Exchange Management Shell to set up your availability address space for you. You can use this to create a new availability address space or to change the credentials of an existing one. This is all one line of code, but we encourage you to read it first before execution.

Note: this will remove and re-add any existing availability address space with this name (to make it easy to update the credentials for an existing availability address space).

if ((Get-AvailabilityConfig) -ne $null) {
Set-AvailabilityConfig -OrgWideAccount;
} else {
New-AvailabilityConfig -OrgWideAccount;
$password = echo ‘x5LPh21NXLoYJFG-ewP1MS74QJRjCSSjV9n7l1OH4qCaINUJUfKLMkBQpmXAqPkN’ | ConvertTo-SecureString -asPlainText -force;
$credentials = New-Object System.Management.Automation.PSCredential -argumentList ‘\sj’, $password;
Remove-AvailabilityAddressSpace -ErrorAction SilentlyContinue -Confirm:$false;
Add-AvailabilityAddressSpace -forestName -accessMethod orgwidefb -credentials $credentials -targetAutodiscoverEPR

Credential shown here are only for representation.

  • Now verify that AvailabilityConfig and AvailabilityAddressSpace have been populated as required.
  • Now start doing free/busy test.
    • You would need to create mail contact in Exchange Online for Google Apps users.12.apps
    • There is no need for mail contact in Google Apps.13.apps

Thank you for reading, please share your feedback !