An email from Satoshi Nakamoto, dated November 8, 2008, has resurfaced, shedding light on Bitcoin's difficulty adjustment mechanism. Shared by the Bitcoin-focused account Documenting Bitcoin, the email explains how the difficulty level adjusts in response to changes in computing power to ensure a steady rate of Bitcoin production. This correspondence was sent just eight days after the release of the Bitcoin white paper, highlighting the foundational principles of Bitcoin's design.