Hillary’s claim is that she sent or received 60,000 emails of which 30,000 were personal (as determined by herself and by her lawyers).
Hillary was SoS for four years (365 days * 4 years) = 1460 days, give or take (she was in office between January 21, 2009 – February 1, 2013).
60,000 emails divided by 1460 = she transacted with 41.3 emails a day (sent or received), in total.
Since the claim is ½ of those emails were personal, we have a US Secretary of State dealing with only ~ 20 official emails a day, sent or received, assuming all these numbers do not include spam.
That number by itself is a practical impossibility.
Number of emails on Weiner’s laptop (600K) could be closer to the reality.