As much as I love the service and enjoy the transparency, I do wonder about the future of smaller operator services as the Internet continues it's descent into a giant mess :-)
Love the keyboard shortcuts in the web interface, killer feature. Also the rules management and folder management is beyond what a lot of other similar providers offer.
Chatmail relays can be run by anyone, they are designed to be fairly minimal and lightweight, just running what is needed to support the "encrypted chat" part, not regular email.
Books mentioned on Hacker News in 2025 https://news.ycombinator.com/item?id=46345897