An anonymous researcher, CipherionX, posted the emails on the bitcointalk forum on August 11th, having retrieved them from the former Bitcoin Core developer Mike Hearn. The first email and reply were shared then curiously , In 2013, Hoskinson was working on a project to archive Satoshi’s emails. They do reveal a few things about Satoshi’s initial plans and thoughts for Bitcoin.
Image and reference : crypto-news
Also CipherionX said that the emails were shared in advance of a website being developed on the history of Bitcoin
When asked about how Satoshi arrived at the “magic numbers” of 21 million coins (Bitcoin’s approximate final cap), he simply replied: “Educated guess, and the maths work out to round numbers. I wanted something that would be not too low if it was very popular and not too high if it wasn’t.” He further conceded that the 10-minute block target was also a guess.
“Bitcoin has long outgrown Satoshi. I know it won’t happen, but I would love to see him come back and contribute once again, though I won’t expect his vision to be the driving force behind Bitcoin’s future”, wrote CipherionX.