Clinton Email Logistics Are Confusing

I do not understand the logistics of the emails. Mrs. Clinton was Secretary of State for approximately 1,461 days (the years 2010, 2011, 2012 plus ten months of 2009 and two months of 2013). The 31,830 private emails averaged 21.8/day, plus nearly that many for business. Call it 40 total/day. Assume Mrs. Clinton sleeps four hours/day, leaving 20 hours for everything else including emails (at an average of two emails/hour all day every day) and meetings with foreign ministers. Some of the business emails would have been complicated and would have required some thought and some time—multiple drafts and staff debate—in creating the reply. To be sure, threads with multiple emails would account for some of the total, but how many? I presume that Mrs. Clinton was not the person at the keyboard entering the reply. (Does she type?)
From my perch in the wilds of New Mexico, it appears that she had to have some help in managing this process. How did that work? What was the decision process with regard to eliminating the personal emails? Highlight all and hit delete?