Outlook add-ins enable customers to access their favorite apps right in email to get more done, faster. As we bring more add-ins in Outlook to help users be more productive, we want to ensure that Office 365 administrators have tools to quickly and easily deploy add-ins. Last year, we announced the availability of Centralized Deployment for Word, Excel and PowerPoint add-ins. Starting February 26, 2018, we will begin rolling out Centralized Deployment for Outlook add-ins, initially in preview, to Office 365 commercial customers.

How to get started with Centralized Deployment for Outlook add-ins?
Administrators can deploy Outlook add-ins to individual users, groups or an organization with ease, right from the Office 365 administration center or using PowerShell scripts. Both Microsoft AppSource add-ins as well as custom add-ins built internally for use within your organization can be deployed using Centralized Deployment to tenants worldwide.

To deploy an add-in, go to Settings > Services & add-ins in the Office 365 admin center.

Clicking “Upload add-in” will take you to the Centralized Deployment page and then you can choose to deploy an add-in from the Office Store/AppSource or from a manifest file

You choose the right visibility for the add-in by either enabling it by default for everyone or give end users options to enable or disable it. You can choose to deploy the add-in to users, groups or your entire organization.

For more details and step by step instructions, review the documentation on Centralized Deployment.
We hope that Centralized Deployment makes it easier for you to deploy add-ins in your organization and look forward to your feedback in improving the experience further.

Frequently Asked Questions

Q. Can I target users and groups in Centralized Deployment?
Centralized Deployment supports deploying to users in top level Office 365 Groups, distribution lists and security groups. Centralized Deployment is not supported for nested groups.

Q. Which Outlook clients can I deploy to using Centralized Deployment?
Centralized Deployment can be used to deploy Outlook add-ins in commercial Office 365 tenants across Outlook on the web, Outlook 2013 and Outlook 2016 for Windows, Outlook 2016 for Mac as well Outlook for iOS and Android.

Q. What languages and worldwide Office data centers are supported?
Today, we have worldwide support for Centralized Deployment for all supported Office languages. We also support the Microsoft Office sovereign datacenters for Germany.

Q. What type of deployment telemetry is available
Telemetry for IT administrators to see data about add-in deployments and usage will be available shortly in the Office 365 admin center. Developers telemetry for add-in deployments is available via the Office ISV Seller Dashboard.

Q. As an administrator, how do I manage access to add-ins for my organization?
For easy deployment of add-ins to users, groups or your organization, we recommend administrators use Centralized Deployment. For other access controls like preventing users from accessing certain add-ins, refer to the Add-ins for Outlook TechNet article.

Q. Will add-in deployment via Exchange Admin Center still be supported?
Yes, add-in deployments via Exchange Admin Center will continue to be supported. However, we recommend customers use Centralized Deployment to deploy add-ins moving forward.

Source: Centralized Deployment for Outlook add-ins will now be available in preview - Microsoft Tech Community