---
title: "Opensense Outlook Add-in Integration with GCC High Environments"
slug: "opensense-add-in-integration-with-gcc-high-environments"
updated: 2026-06-30T12:55:13Z
published: 2026-06-30T12:55:13Z
canonical: "help.opensense.com/opensense-add-in-integration-with-gcc-high-environments"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://help.opensense.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Opensense Outlook Add-in Integration with GCC High Environments

Opensense supports deployment in Microsoft 365 Government Community Cloud (GCC) High environments, which are isolated, non-routed solutions designed for federal agencies and organizations handling sensitive government data.

### Key Requirements

- **Exchange Online or Microsoft 365** running minimum version 2104 (Build 13929.20296) with API v1.10 support
- **Modern Authentication** must be enabled for secure communication
- **Custom manifest deployment** using the GCC High-specific manifest URL
- **Azure AD enterprise application** for directory synchronization in the isolated environment

### Deployment Overview

Unlike standard commercial Microsoft 365 environments, GCC High requires:

1. **Custom Add-in Deployment**: The add-in must be manually deployed through the Microsoft 365 admin center Add-ins section using a GCC High-specific manifest file, rather than through the standard Integrated Apps portal
2. **Dedicated Directory Sync Tool**: A specialized Azure AD enterprise application ("Opensense GCC High Directory Sync tool") is required to securely synchronize directory information within the isolated GCC High environment
3. **Portal Configuration**: The Opensense Portal must be configured with the "Office 365 GCC High" toggle enabled to ensure proper routing and authentication
4. **Proxy Allowlisting**: Organizations using web proxies (such as zScaler) must allowlist specific Opensense domains to enable the add-in to function properly

### Mobile Add-in Considerations

In GCC and GCC High environments, mobile add-ins are disabled by default. Administrators may need to modify tenant configuration settings using Exchange Online PowerShell to enable mobile add-in functionality. See [Using the Outlook Mobile Add-in within GCC Environments](https://help.opensense.com/docs/using-the-outlook-mobile-add-in-within-gcc-environments) for details.

### Implementation Support

Due to the specialized nature of GCC High deployments and the security requirements involved, Opensense provides dedicated implementation support. Contact your Opensense representative or support team at [help@opensense.com](mailto:help@opensense.com) for assistance with GCC High deployment.