Centralized Deployment
The Microsoft 365 admin feature that installs an Outlook add-in for users or groups.
Centralized Deployment lets a Microsoft 365 admin install an Outlook add-in for the whole organisation, specific groups or individuals from the admin center, under Integrated apps.
Users do not need to install anything. The add-in can take up to 24 hours to appear in every mailbox after deployment.
Signature add-ins use event-based activation to run when a new message is composed and insert the current signature.