So - this basically says that they ran algorithmic metadata searches of 650K emails and did not find any new emails.
That's it.
The investigation is still open, she still needs to be held accountable for the fact that no less than 5 nations, hostile to the US, gained access to this unsecured server with confidential state secrets that put our operatives overseas in grave danger (Remember when the Iranian scientist was put to death shortly after her server was breached?) and made us more insecure here.
This letter is much ado about nothing, really. The investigations (both of her criminal negligence and the Clinton Foundation) are still ongoing, and she is still a corrupt, unindicted felon. The lemmings that support her Marxist rhetoric as still in lockstep regardless.
Perhaps some undecided voters were swayed by the reopening of the case, & many of those have since early voted, or are still suspicious as he specifically did not close the investigation. In the end, the whole episode negatively affects her credibility more than this letter is going to help her.