I need to activate notification email on IBM WebSphere Network Deployment when the application servers are out of sync.
I do not think this is possible since every time you make a change to your master configuration you need to synchronize with the node agent to apply it to the application servers. It is not a defect but a natural situation when you make changes to your (distributed) architecture.
In case you have problems with synchronization you can just set up Automatic synchronization or else examine your synchronization strategy.
The following should be useful: