Note: Before you begin, confirm that your organisation meets all requirements for using Centralised Deployment, as described in Determine if Centralised Deployment of add-ins works for your Office 365 organisation.
If your organisation meets all requirements, complete the following steps to publish an Office Add-in via Centralised Deployment:
Step 1: Downloading the manifest
Addins are installed into Outlook using manifest files. This can be accessed here: https://spaceconnect.blob.core.windows.net/prodrelease/OutlookWebAddIn.xml
The file contains code that is used by Outlook to install addins. The file should be downloaded and then uploaded into Outlook. It is not an install package and opening it will just display the xml code.
Step 2: Sign in to Office 365
Sign in to Office 365 with your work administration account.
Step 3: Open "Services & Addins"
Select the app launcher icon in the upper-left and choose Admin.
In the navigation menu, press Show more, then choose Settings > Services & add-ins.
If you see a message on the top of the page announcing the new Office 365 admin center, choose the message to go to the Admin Center Preview (see About the Office 365 admin center).
Step 4: Deploy Addin
Choose Deploy Add-In at the top of the page. This will open a panel with guided steps for installing addins. After reviewing the requirements, Choose Next .
Step 5: Upload Manifest
Choose the following options on the Centralised Deployment page:
If you downloaded the manifest file to you machine, then select the option "I have the manifest file...".
Alternatively, select the option for "I have a URL" and enter: https://spaceconnect.blob.core.windows.net/prodrelease/OutlookWebAddIn.xml
Step 6: Finish
When finished, choose Save to save the manifest. This process may take up to three minutes.
Then, finish the walkthrough by pressing Next. You now see your add-in along with other apps in Office 365.
Note: You will need to restart Outlook for the new addin to become visible in the ribbon menu.