The question is why a private server was being used. A SOS should know that all activity on the net would be looked into whether it was going through a private server or a governmental server. Either she didn't know, or she did it for a reason. If she did it for a reason, the question is what reason.
The first question then would be if she was in fact trying to cover up something. If so, what would she be covering? Something that did not go well with her position as SOS.
Next, what could that possibly be? Most likely, but not necessarily, private affairs in conflict with her SOS role.
What could that be? Something generating power, money, or both. Something that her SOS position made possible.
Well, that would be a start.