12500000000 / 547.5 (1.5 years) == roughly 23m e-mails per day over the 1.5 year sample. 1500000000 / (6 * 7) (6 weeks) == roughly 35m e-mails per day over the

12500000000 / 547.5 (1.5 years) == roughly 23m e-mails per day over the 1.5 year sample. 1500000000 / (6 * 7) (6 weeks) == roughly 35m e-mails per day over the past six weeks.