Your question was discussed tonight on MNBC. All presidential communications are by the nature of the office withheld from public view automatically.
The contents may be nothing at all, given that Obama, personally and professionally, pretty much had Hillary on ice mostly anyway, away from anything he deemed important.
I do see your point but I think getting those weapons to his terrorist friends via Benghazi was pretty important to him.
Important enough for him to let 4 people be killed over it.
The ultimate responsibility for that fiasco lays at Obama's feet.
I hate when people say this, but see my tagline.