All part of the ‘draft’ technique.
You create a DRAFT EMAIL and don’t send it. You give your phone to whomever you want to communicate with, and get a new phone with the same number.
The other person, whom you give the phone to, can then see your EMAIL and look at the DRAFT. Once read, they delete it. It never gets ‘sent’ through any ‘servers’ and the evidence is gone. Well, you have to smash the phone to destroy any data left on it (like a PC, deleted files are not actually ‘erased’) but there are reports that is what she did to several phones.
Sounds like exactly what she did.
And she wants us all to think she’s a tech-ignoramus.
Comey bought it lock stock and barrel.