No, this is not a classified document.
It is just a cover letter (below), and when separated from the attachments mentioned in the cover letter, it is UNCLASSIFIED.
The cover letter indicates that the attachments in question are former Secretary of State Clinton’s emails sent over the internet. The intelligence community (IC) analysis shows that some of the emails are classified up to the TOP SECRET//SI//TK//NOFORN level. What does this mean? The three classification levels (TOP SECRET, SECRET and CONFIDENTIAL) are ranked in order of the damage that compromise would do to national security. TOP SECRET is the highest category, and is information that would cause exceptionally grave damage to national security if compromised.
The emails in question are even more sensitive than TOP SECRET with the additional caveats of SI and TK. You will have to Google those two terms, but you should know that the type of information held to be that level is extremely sensitive. NOFORN means no foreign nationals can access the information. I would suggest that anyone holding cabinet rank would realize (or should have realized) that the information should not be sent over unsecure or UNCLASSIFIED email. She was not the HUD Secretary. This is a Secretary of State that cannot recognize highly classified information when she sees it. TOP SECRET//SI//TK//NOFORN level was protected as it if were UNCLASSIFIED. Was it because she couldn’t recognize the difference, or because she was reckless? Even if the information was not (yet) marked as classified, it should be clear that it is classified at a high level. At best, we are talking about a “spillage” incident in which classified information is transmitted via a network not accredited for the sensitivity of the information.
Anyone who has ever held a security clearance would likely recoil in “I can’t believe it” horror at the thought of sending TOP SECRET//SI//TK//NOFORN information over the internet. Then there would be the ugly, ugly repercussions…..
So here is the cover letter to the IC evaluation of those emails. I downloaded it from Senator Chuck Grassley’s (R-Iowa) Senate website. Don’t freak out when you see the top and bottom markings.