“Why can they not subpoena the recipients e-mails (other then the fact the R’s are scared s-—less of the beast).”
First one has to know the identity of all the people to whom she addressed and copies and blind copied emails. Of the people one’s common sense tells us must have been email correspondents, one would need a broad subpoena, ordered that all emails to and from Hillary and that person be produced.
Her inbox containing inbound email was probably the most damaging. The inbox contents might indicate direction was given to her to engage in political activity.
The outbound email could demonstrate the directions she was giving to others. It could also include reports to her superiors apprising them of her activitites.
But we all know the truth: The R's are not going to get serious about this because they are either cowards, or content with being in second place.