DKIM2 and DMARCbis have landed, and Stalwart speaks them first
Email authentication just took its biggest step in a decade. DKIM2 rebuilds DKIM around a verifiable chain of custody that survives forwarding, stops replay, and makes bounces provable, while DMARCbis trades the Public Suffix List for a live DNS tree walk and writes a decade of operational lessons back into the spec. Both are now fully implemented in Stalwart v0.16.12, the first mail server to support them, and both can be tested straight from the browser at the mail-auth playground.