Why should I give Domain Admin rights to the Notification Server AppID?
Most applications used on the Notification Server usually push an Agent or subagent that needs to be installed on client machines. Since the installation needs to run on the local machine, having an account without Admin privileges can cause the application not to run or execute properly. It is a lot more convenient to use a single account rather than having to manually specify the Local Admin account for each machine. Also, any Application/Solution that requires some type of authentication to install, execute or run locally on a client machine is easier to configure as well.