Don’t forget the spam, too.
Yes - I tried to use very conservative numbers. If we assume, per day, 10 incoming e-mails responded to (that’s the 20 per day right there), 10 per day saved / legit, but not responded to, 5 “spam” per day, 10 accounts, for 8 years, we’re up to 924,000 e-mails.
A lot of the suspect e-mails appear to be short, too. We are not talking about lengthy compositions, for the most part.