[vacri]

There’s 2.3 billion email users worldwide, and the average mailbox stores 8,024 messages.

versus

150 billion emails each day

These numbers do indeed fail the sniff test. This would mean that the average age of a mailbox would only be ~120 days (150B/2.3B daily mails/user = ~65, 8000/65 user account size/dail user mails= ~120 days). That's a mere four months. Of course, this is only if people aren't regularly deleting mail, but it gives an idea of how far out of whack the estimates are.

Later on, it's mentioned that 70% of mail is spam. Going from that same 150B number, that would mean that the average user would get ~20 emails per day that weren't spam. This is the average user, whose mailbox is only 4 months old, and probably hasn't signed up to all that many services...

[raindrift]

I based my estimates on the best numbers I could find. That said, my spam numbers were in fact incorrect (spam is small and gets deleted). Accounting for that, people save an average of a year's worth of email.

If you look at the growth in email users over time (~6%/year), most accounts are probably > 1 year old. I'd assume the disparity comes from people deleting messages.