In this episode, in association with the ACM ByteCast, Scott talks with Eric Allman, one of the foundational figures of the early internet. Best known for creating Sendmail, the mail transfer agent that powered a large portion of global email infrastructure through the formative years of the network, Allman helped shape how messages move across the internet. Their conversation explores the origins of internet email, the messy realities of building software that must operate at planetary scale, and what lessons today’s engineers can learn from the systems and design decisions that quietly underpin modern computing.