Does anyone here believe the FBI was able to read 650,000 e-mails in one week?
Have a human read them? No.
Fortunately, we have these things called computers that allow for searching text very very quickly and, using moderately intelligent parameters, very intelligently. So it would be possible to quickly eliminate all of those emails that had already been analyzed earlier in the search, and from the remainder to eliminate all of those that were not to or from Hillary Clinton, leaving a manageable number that could be read by a staff of agents in a reasonable time frame.