Messages being received on all devices instead of specific ones

Pushover's API and Delivery Groups support restricting messages to be sent to a specific device (or multiple specific devices) on a user's account, rather than sending it to all devices which we do by default.

When the device being specified in the device parameter through our API or the device column in a delivery group does not exist, has been renamed, or has been temporarily disabled, messages being sent to that user will instead be directed to all other active devices on the user's account.

This behavior is by design so the message to the user is not lost, and to alert the user that the device being targeted is either offline or specified incorrectly so it can be updated.