I also like idea of getting a judicial expert to look into finding alternate sources of the emails. I suspect that IRS servers, other peoples computers (like in the White house and DNC) along with the NSA could do wonders to come up with real information that IRS and DOJ are corrupt and doing the Big Zero's bidding.
I can say this...having worked around government operations...that once someone says the boss has to give testimony under oath...things get awful messy. The boss will have several lawyers standing in a room as he questions his junior executives, and he might require them to sign statements as they answer his questions. At that point, the junior guys call their lawyers, and question-and-answer sessions with the boss suddenly get stagnant. No one will sign any statement....no one will vouch for anything....and the whole system falls apart within two or three weeks.
I can also vouch for this. Almost all of the chiefs of various government agencies....have zero knowledge or understanding of their networks, IT strategies, their back-up plan, or how email works. This is one of the reasons why they all spend four-hundred percent of the necessary budget on their network/IT requirements. It’s why they have $150k a year IT engineers in their back-up department, when a $50k a year junior engineer would be sufficient.