Microsoft is pleased to announce the updated architecture of Outlook for iOS and Android meets all the FedRAMP requirements which are FISMA compliant and based on the NIST 800-53 rev3. The security requirements have been approved by a third-party assessment organization and passed the independent audit assessment which gives Office 365 Government Community Cloud (GCC) customers the ability to adopt Outlook for iOS and Android.   


This update brings the necessary components of the Outlook for iOS and Android architecture into the accreditation boundary of Office 365 and enables GCC customers to accelerate the adoption of this secure mobile email and calendar solution. 


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With controls in place to ensure mailbox data transfer and storage security practices are consistent with the most advance cloud solutions, US Office 365 GCC customers can also confidently use mobile application management tools such as Microsoft Intune to manage device access and mailbox policies for their mobile users.


Continuously enhanced with advanced capabilities across email, search and calendar, Outlook is the connected to the apps and services to help focus on what’s important and get more done. For GCC users, it’s the best way to experience Office 365 on your mobile device.



Q: Who can use the Office 365 Government Cloud Community for Outlook for iOS and Android?

A: All customers with US Office 365 GCC tenants are eligible to use the new architecture. This includes:

  • US GCC customers who are new to Office 365
  • US GCC existing customers who previously were blocked from using Outlook for iOS and Android
  • US GCC customers who obtained a waiver from being blocked and now want their users to connect via the Azure Government Community Cloud.


Q:  When will GCC users be able to set up "GCC Mode" in Outlook on their mobile device?

A:  The Outlook for iOS and Android app that supports the new architecture is rolling out in the iTunes app store and the Google Play store this week.


Q: How will I find out if all my organization’s users are using Outlook for iOS and Android?

A: Customers can look at individual user’s status by accessing the user’s Mobile Device details from the Exchange Admin Center in Office 365 or via PowerShell. If a user’s Mobile Device details show ‘Client Type = REST’ or ‘User Agent = Outlook-iOS/2.0 OR Outlook-Android/2.0’, this signifies the user is using Outlook on their mobile device.


Q: If our organization was previously whitelisted and using the public Azure instance, what will the end user experience look like when enabling the new GCC mode? 

A: When switching to GCC mode, existing accounts will be removed.  Users will need to re-add their accounts the next time they open the Outlook app.


Q: Will Office 365 GCC customers be able to add an account to Outlook for iOS and Android in non-GCC mode?

A: No. GCC users will continue to be blocked from adding accounts with Outlook for iOS and Android as that process routes data via the public Azure cloud instance. Controls are in place to ensure all GCC mobile users use the “GCC Mode” to connect Outlook with their Office 365 account.


Q: Once a user enables “GCC Mode” can they add an additional Office 365 account?

No, Office 365 Government Community Cloud customers may only have one account connected to Outlook for iOS and Android from a single Office 365 instance. This means that these customers cannot have a mailbox that is located on a different Office 365 tenant, from either the public Office 365 instance or the Office 365 Government Community Cloud tenant within the same Outlook for iOS and Android app on the same device.


Q: What is the experience for Office 365 US Government Community customers who are already using the Outlook app today?

A: The administrators of Office 365 U.S. Government Community tenants who may have been granted permission to use the public Azure environment for Outlook for iOS and Android should contact Support to get their domains removed from the whitelist and direct their users to follow the instructions to enable “GCC Mode”. Instructions can be found here.


Q: What is the experience for Office 365 US Government Community customers who are not already using the Outlook app?  

A: In our new Office 365-GCC based architecture, data passes through Microsoft Azure Government Community datacenters within the United States and fully complies with the control commitments in the FedRAMP compliance package for Office 365 US Government Community.

GCC customers will no longer be blocked from using Outlook for iOS and Android and the app now supports a new “GCC Mode” which should be enabled in the app.   Instructions can be found here.


 Q: What is the experience for US Government Defense customers using Outlook for iOS & Android?

A: Customers with tenants in US Government Defense are blocked and unable to connect to their Office 365 mailboxes via Outlook for iOS & Android. They will continue to be blocked until we deliver support for these instances.








Why can't multiple mailboxes even from the same GCC tenant be added in Outlook for iOS and Android?

We have users who are delegates of other mailboxes, have full control of multiple mailboxes or need to access shared mailboxes all within the same GCC tenant.  


Hi, We just migrated to this yesterday.

Please help quickly to allow multiple accounts within the same agency - perhaps for specific users with specific permissions - somehow. This is an extremely debilitating change for assistants and other delegates who manage multiple schedules and need access to others' email accounts and calendars to do their daily tasks.


As an assistant and a manager, this change is impacting my daily work and the daily work of my assistants.


Besides which, it happened all once, with no warning and no alternatives provided.


Thank you.