Re: Comey was required by Congress to inform Congress
Her predecessors handled email much, much differently than she did, in many ways.
Most obvious is that they didn't send classified information through their non-government email. Some staffers sent some very low-level information to Rice, but were corrected immediately. Clinton actively encouraged her staff to bypass classification, according to her own emails.
Less obvious is that, when Powell and Rice did it, they still used their government accounts for the bulk of their work, with very few used through their other accounts. Clinton completely relied on her private server for all of her work emails.
Clinton also lied flat-out about it, from first claiming that the server didn't exist, to claiming that it was only one unsecured email device - when it turned out to be over a dozen, some of which were lost, and others destroyed AFTER the investigation found out about them. That sort of action would land you in jail if you tried something similar when dealing with evidence in a government investigation...
The last part - and the part you managed to miss - is that between the time Colin Powell and Condi Rice held office and the time Hillary and the Democrats took over, the law changed, making it illegal to use private email servers. Hillary knew this.