How to manually deploy the add-in for all users (Office 365 admin)

The Outlook add-in can be deployed in certain cases using a custom manifest file (offline) or a custom deployment package.

  1. Download the manifest file for the Outlook Add-in.
  2. Log in to the Office 365 Admin Portal.
  3. Click Settings to expand that section and then click Services & add-ins.
  4. Click Deploy Add-in.
  5. Click Next.
  6. Click Upload custom apps.
  7. Click I have the manifest file (.xml) on this device.
  8. Click Choose File, and select the file manifest file.
  9. Click Upload.
  10. Choose the user assignments and deployment method, then click Deploy.
  11. Once the deployment is finalized, click Close.