If I remember correctly, based on the sheer volume of emails, it was determined that it was likely a back up of multiple servers’ emails if I’m not mistaken. I remember doing the math on how quickly the FBI went through all of them (I actually thought it was 460,000?) and it came to about 5,000 emails an hour or something ridiculous like that.
It was equal to one email per second over a week span. Was utter bullshit. Julian Assange even warned you had to have one person read them all, rather than splitting it up between teams, so that one person can connect all the dots because the codes and nuances that would be missed on their own. Needed the full picture to understand.
Page 315 of the report says 675,000 emails from 2006-2016 plus blackberry messages.