At this point it is not so clear that her emails would have been any more secure on a government server.
It’s not going to come through her scrubbed and shredded server. It’ll come through the contact she’s had with others. Seize her phone records, find out who she makes the most phone contact with, and go after their servers.
That’s where you’ll nail her.
Or...if I’m Trump...place a $10,000 bounty on any email that comes from her personal email address during her tenure as SOS.