server[S] ideas:

[S] = "Seagate" (pg147 from JudicialWatch pdf);

[S] = "Strzok" (flipped/forced to provide)

[S] = "#19" (19th letter of alphabet, as in total # of servers).

[S] = "Schmidt, Eric" (if .pst archives auto-archived to Google Cloud Server)

>>2437994

Good dig.

[S} could also be "Successor" Server.