It was interesting to read
https://www-secure.symantec.com/connect/forums/how-does-one-configure-sepm-121-manage-out-network-computers
but it contained some links to technical articles that don't work any more.
Since the thread is locked the only thing ou can do is start a new discussion, so here we are.
Is this still possible (especially with Windows 10)? Are there updated links to the content?
I couldn't find any updated HOWTO for that, but here's one that is similar with regarding to creating the Management Server List
https://www-secure.symantec.com/connect/forums/management-server-lists
You mean ones that go off network? You could put a SEPM in your DMZ
Best Practices: Configuring a Symantec Endpoint Protection environment in a DMZ