Administrator setup for GSSMO

G Suite Sync for Microsoft Outlook

If you have the legacy free edition of G Suite, upgrade to G Suite Basic to get this feature. 

This article is for G Suite administrators. To begin using GSSMO, go to GSSMO User Help.

You can set up G Suite Sync for Microsoft Outlook (GSSMO) for users in your organization so they can synchronize their email, calendar, and contact data between G Suite and Outlook.

Before you begin installation and setup, make sure you meet the system requirements.

System requirements

Note: As Microsoft no longer actively supports these platforms, support for Microsoft Windows XP and Microsoft Windows Server 2003 in our data migration and sync products stopped on December 31, 2018. Learn more

Operating system requirements

  • Microsoft Windows Vista SP1 (32 bit and 64 bit)
  • Microsoft Windows 7 (32 bit and 64 bit)
  • Microsoft Windows 8 (32 bit and 64 bit)
  • Microsoft Windows 10 (32 bit and 64 bit)

Regardless of which version of Windows you’re using, we recommend you update to the latest patches for that version.

Note: GSSMO isn't supported for Apple Mac. Microsoft Outlook for Mac doesn't support the Messaging Application Programming Interface (MAPI), which GSSMO needs to communicate with Outlook.

Outlook requirements

  • Microsoft Outlook 2003 SP3
  • Microsoft Outlook 2007 SP2 (or SP1 with hotfix)
  • Microsoft Outlook 2010 (32 bit and 64 bit) with Service Pack 2
  • Microsoft Outlook 2013 (32 bit and 64 bit)
  • Microsoft Outlook 2016 (32 bit and 64 bit)
  • Microsoft Outlook 2019 (32 bit and 64 bit)

Note: Microsoft no longer actively supports Outlook 2003 and Outlook 2007. We recommend you upgrade to a supported version of Microsoft Outlook.

Permissions for users

To install GSSMO, users must have local administrator permissions for their machines.

Port requirements

Open port 443 for the following applications on each client machine:

  • Outlook.exe
  • ProfileEditor.exe


GSSMO uses HTTPS to connect to Google services using a proprietary GSSMO-specific Gmail sync protocol. It also uses the following APIs:

GSSMO doesn't use IMAP or SMTP.

Set up and install GSSMO

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Step 1: Set up GSSMO in the Google Admin console

Turn on the following features in your Admin console:

  1. Sign in to the Google Admin console.
  2. Turn on GSSMO for your account:
    1. From the dashboard, click Appsand thenG Suiteand thenGmailand thenEnd User Access.
    2. Click G Suite Syncand thencheck the Enable G Suite Sync for Microsoft Outlook for my users box.
    3. Click Save.
  3. Turn on the Google Calendar service (so users can create profiles). For details, go to Turn Calendar on or off for users.
  4. Turn on contact sharing (so users' Global Address Lists are dynamically updated):
    1. From the Admin console Home page, go to Menu and thenDirectoryand thenDirectory settings.
    2. Click Sharing settingsand thenContact sharing.
    3. Select Enable contact sharing.
    4. Click Save.
  5. Turn on the Drive service and Drive apps (required to synchronize notes to Drive):
    1. To turn on Drive, go to Turn Drive on or off for users.
    2. To allow users to install Drive apps, click Appsand thenG Suiteand thenDrive and Docsand thenFeatures and Applications.
    3. Click Drive SDKand thencheck the Allow users to access Google Drive with the Drive SDK API box.
    4. Click Save.
Step 2: Install GSSMO

Users in your organization who want to sync their data between G Suite and Outlook must have GSSMO installed on their client machine. There are 2 options for installation.

Option 1: Push an MSI file to your users

To do this, download the MSI file from the GSSMO download page. Be sure to pick the correct edition (32 bit or 64 bit) for your users' version of Outlook.

You can then push the MSI file to your users with the software you use to deploy and secure your organization's applications.

Your users can then follow these instructions to install the file.

Option 2: Let your users download and install GSSMO themselves

Your users can download the EXE file from the GSSMO download page.

They can then follow these instructions to install the file.

Install location

The default location on each client machine is C:\Program Files\Google\Google Apps Sync.

Step 3: (Optional) Set up free/busy information for Exchange users

If you're using GSSMO in a mixed G Suite and Microsoft Exchange environment, and you want to query availability information for Exchange users, you need to:

  1. Install and set up Google Calendar Connector Web Service. For instructions, go to Google Calendar Connector Web Service Installation and Configuration Guide.

    Important: When you set up the web service, make sure you do not set up the Google Calendar Connector Sync Service.

  2. Create the following registry key and accompanying string value on each client machine where GSSMO is installed. If you're running a 32-bit version of Outlook on a 64-bit version of Windows, create this registry key in the correct location for 32-bit applications. For details, consult these instructions on using the Windows registry at Configure options through the registry.
    • Registry key— HKEY_CURRENT_USER\Software\Google\Google Apps Sync\CalendarSync
    • String value—Value name: FreeBusyURL; Value data: <URL for the Calendar connector>

      Example (where you replace MY_COMPANY_FREEBUSY_SERVER with the name of your company's server)

Note: Google Support cannot assist with troubleshooting your Google Calendar Connector Web Service installation.

Import data

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Integration with G Suite Migration for Microsoft Outlook

With GSSMO, your users can import data from an Exchange account or Outlook PST file. To do this, GSSMO uses a separate migration product, G Suite Migration for Microsoft Outlook (GSMMO). GSSMO launches the GSMMO migration product automatically and, in most cases, users won't even notice they're using a separate product.

GSSMO launches the migration product when the user:

GSMMO as a standalone migration product

Users can launch GSMMO as a standalone application. In the Start menu, click G Suite Migrationand thenG Suite Migration for Microsoft Outlook.

However, GSMMO doesn't import Outlook notes, tasks, or journal entries. To import this data, users should run GSSMO.

How do I install the GSMMO migration product?

The GSMMO migration product must be installed on each client machine.

Users who download and install GSSMO themselves (Option 2 above) automatically install GSMMO migration product.

If you push GSSMO to users via an MSI file (Option 1 above), you’ll also need to push the GSMMO migration product to them as well. Or, have them install GSMMO themselves. For details, go to Install GSMMO.

What's imported?

Users can sync email, contacts, calendar events, and Outlook notes, which are then available in Outlook and the G Suite web interface.

Outlook tasks sync to G Suite but only after GSSMO starts. (Email, contacts, and calendar events sync while importing.)

Outlook journal entries are not synchronized to G Suite, but users can import them from their Outlook profile during the initial sync.

For details, go to What's synchronized between Outlook and G Suite?

Get help

The Google Cloud Support Center provides support for GSSMO and GSMMO, but not for Outlook or Windows. If you have additional Outlook or Windows questions, consult your Microsoft documentation.

Google, Google Workspace, and related marks and logos are trademarks of Google LLC. All other company and product names are trademarks of the companies with which they are associated.
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