If the Notification Server is the only server in your environment, and you want to deploy Images, there is a slight modification needed to be made on the Notification Server.
This applies to SMP 8.6 and above
Since the Notification Server is a Package and Task Server out of the box, we need to add the Deployment Task Server Component plugin to the environment.
Important -- Do not add the Package Server component to the Symantec Management Platform as this duplicates all software and image resources thus doubling the disk space.
Got to "Settings > All Setting > Agent\Plugins > Deployment > x86 or x64 > Deployment Task Server Component Install" and enable this policy.
Open the Symantec Management Agent on the Notification Server and run 'Update Configuration'.
After the policy runs you will see the Deployment Task Server Component in the list of Agents/Plugins in the Symantec Management Agent.