Set up G Suite for Outlook for your users

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 page is for G Suite administrators who want to set up G Suite Sync for Microsoft® Outlook® (also known as GSSMO) for users in their organization. Before you begin, make sure you meet the system requirements and complete the setup and installation. Then, your users can start using GSSMO to synchronize their data between Outlook and G Suite.

I'm not an administrator

To begin using GSSMO, see the GSSMO User Help Center.

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System requirements

G Suite requirements

This feature is available with G Suite Enterprise, Business, Basic, G Suite for Education, and Nonprofits edition. Compare editions

Operating system and Outlook requirements

Note: As the platforms are no longer actively supported by Microsoft®, support for Windows® XP and Server 2003 was discontinued on December 31, 2018. Learn more.

Operating system requirements

Note: Regardless of which version of Windows you are using, we recommend that you upgrade 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 is required for GSSMO to communicate with Outlook.

Outlook requirements

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

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

Permissions for users

In order to install GSSMO, users must have local administrator permissions for their computers.

Port requirements

Open port 443 for the following applications on each computer:

  • 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 does not use IMAP or SMTP.

Set up and install

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 Apps and then G Suite and then Gmail and then End User Access.
    2. In the G Suite Sync section, check 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, see Turn Calendar on or off for users.
  4. To use the Global Address List (GAL) Generator:
    1. From the dashboard, go to Security > API reference. Where is it?
    2. Check the Enable API Access box.
    3. Click Save.
  5. Turn on contact sharing (so users' Global Address Lists are dynamically updated):
    1. From the Admin console Home page, go to Menu  and then Directory and then Directory settings.
    2. Under Sharing settings, select Enable contact sharing.
    3. Click Save.
  6. Turn on the Drive service and Drive apps (required to synchronize notes to Drive):
    1. To turn on Drive, see Turn Drive on or off for users.
    2. To allow users to install Drive apps, click Apps and then G Suite and then Drive and Docs and then Features and Applications.
    3. In the Drive SDK section, check the Allow users to access Google Drive with the Drive SDK API box.
    4. Click Save.
Install GSSMO

Users who want to sync their data with Outlook must have GSSMO installed on their computer. You have 2 options for installation.

Option 1: Push an MSI file to your users

To do this, download the MSI file below. Be sure to pick the correct one, which is based on your users' version of Outlook.

Your users can refer to I'm installing GSSMO myself for further instructions.

Option 2: Let users download GSSMO themselves

Users can download GSSMO from the GSSMO download page. They can then follow these instructions to install the plugin.

(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 configure Google Calendar Connector Web Service. For instructions, see Google Calendar Connector Web Service Installation and Configuration Guide.

    Important: When you set up the web service, make sure you don't set up the Google Calendar Connector Sync Service.

  2. Create the following registry key and accompanying string value on each computer 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, see the instructions on using the Windows registry at Configure limits and 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.

Importing data with GSSMO

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 tool, G Suite Migration for Microsoft Outlook (GSMMO). GSSMO launches the GSMMO migration tool automatically and, in most cases, users won't even notice they're using a separate tool.

GSSMO launches the migration tool when the user:

GSMMO as a standalone migration tool

Users can launch GSMMO as a standalone application by going to the Windows Start menu and clicking G Suite Migration for Microsoft Outlook.

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

How do I install the migration tool?

The GSMMO migration tool must be installed on each user's computer.

Users who download and install GSSMO from the download page will install the GSMMO migration tool automatically. If you push GSSMO to users via an MSI file, you need to push the GSMMO migration tool to them as well. Or, have them install the GSMMO migration tool themselves. For details, see Install G Suite Migration for Microsoft Outlook.

What's imported?

Users can import mail, contacts, calendar events, and Outlook notes, which are then available in Outlook and the G Suite web interface. They can also import Outlook tasks and journal entries, which remain available only in Outlook.

Get help

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

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