chore(release): prepare for 1.9.0

CHANGELOG.md

@@ -1,5 +1,31 @@
 # Changelog for chatmail deployment 
 
+## 1.9.0 2025-12-18
+
+### Documentation
+
+- Add RELEASE.md and CONTRIBUTING.md
+- README update, mention Chatmail Cookbook project
+
+### Bug Fixes
+
+- Expire messages also from IMAP subfolders
+- Use absolute path instead of relative path in message expiration script
+- Restart Postfix and Dovecot automatically on failure
+- acmetool: Use a fixed name and `reconcile` instead of `want`
+
+### Features
+
+- Report DKIM error code in SMTP response
+- Remove development notice from the web pages
+
+### Miscellaneous Tasks
+
+- Update the heading in the CHANGELOG.md
+- Setup git-cliff
+- Run tests against ci-chatmail.testrun.org instead of nine.testrun.org
+- Cleanup remaining echobot code, remove echobot user from deployment and passthrough recipients
+
 ## 1.8.0 2025-12-12
 
 - Add imap_compress option to chatmail.ini