On June 16, 2011, top Clinton aide Jake Sullivan wrote to Clinton to say she would get "tps" -- presumably short for "talking points" that evening. The subject of the email is redacted so it's not clear what topic these points covered.
The next morning, Clinton wrote back to say she hadn't received them yet, and after a few minutes Sullivan responded that staff were having issues sending the document in a secure fax but that they were "working on it."
"If they can't," Clinton replies, "turn into nonpaper w no identifying heading and send nonsecure
A State Department official declined to comment on Grassley's statement, but told CNN earlier in the day that the department has "no indication at this time that the document being discussed was emailed to her."
"I'm not going to speculate about whether the document being discussed was classified," this official added. "Generally speaking, I can say that just because a document is sent via a secure method doesn't mean that it's classified. Many documents that are created or stored on a secure system are not classified."
http://www.cnn.com/2016/01/08/politics/hillary-clinton-emails-2016/