The default Stalwart image moves from v0.16.22 to v0.16.27, the last 0.16 release and the one ihasmail now tests against. A loopback deploy (--local) against it set up Stalwart, created a mailbox and signed in to ihasmail 2026.10.27. The README gets a Support section: 0.16.27 supported and the default, other 0.16 releases untested, 1.0 not supported because its first-run setup changed. Troubleshooting's known limits say the same. The README and CONTRIBUTING said the end-to-end test runs every Monday. It has been a job run by hand on a GitHub runner since the move to Gitea.