If you saw my work email, you would believe. 
I get 200 emails a day. 1200 emails a week (200 for the weekends). That is a large amount, comparatively.
1200 X 52 weeks = 62,400 emails/year
And that takes me about half the day to wade through.
At the very best, I could see double that number. But then, Huma couldn't be an aid if she did get that many... as she'd do nothing but stare at a computer screen all day going through emails from morning till evening.
In order for her to function as an aide, she'd have to get less emails just to be able to get away from her desk and actually *DO* something.