Custom notifier must implement jetbrains.buildServer.notification.Notificator interface and register implementation in the jetbrains.buildServer.notification.NotificatorRegistry.
When a notifier is registered, it can provide information about additional properties that must be filled in by the user. To obtain values of these properties, use the following code:
Notifier can also provide custom UI for Notifier rules and My Settings&Tools pages. See PlaceId.NOTIFIER_SETTINGS_FRAGMENT and PlaceId.MY_SETTINGS_NOTIFIER_SECTION.
Notifications are only delivered if there is at least one subscribed user for given event.
User's Guide: Subscribing to Notifications
Administrator's Guide: Customizing Notifications