- **[feat]** Support extra `user_attributes` in accounts configuration ([#1792](https://github.com/docker-mailserver/docker-mailserver/pull/1792))
- **[feat]** Add possibility to use a custom dkim selector ([#1811](https://github.com/docker-mailserver/docker-mailserver/pull/1811))
- **[feat]** TLS: Dual (aka hybrid) certificate support! (eg ECDSA certificate with an RSA fallback for broader compatibility) ([#1801](https://github.com/docker-mailserver/docker-mailserver/pull/1801)).
- This feature is presently only for `SSL_TYPE=manual`, all you need to do is provide your fallback certificate to the `SSL_ALT_CERT_PATH` and `SSL_ALT_KEY_PATH` ENV vars, just like your primary certificate would be setup for manual mode.
- **[security]** TLS: You can now use ECDSA certificates! ([#1802](https://github.com/docker-mailserver/docker-mailserver/pull/1802))
- Warning: ECDSA may not be supported by legacy systems (most pre-2014). You can provide an RSA certificate as a fallback.
- **[fix]** TLS: For some docker-compose setups when restarting the docker-mailserver container, internal config state may have been persisted despite making changes that should reconfigure TLS (eg changing `SSL_TYPE` or replacing the certificate file) ([#1801](https://github.com/docker-mailserver/docker-mailserver/pull/1801)).
- **[fix]** Linting now uses local path to remove the sudo dependency ([#1831](https://github.com/docker-mailserver/docker-mailserver/pull/1831)).
### Breaking Changes:
- **[security]** TLS: `TLS_LEVEL=modern` has changed the server-side preference order to 128-bit before 256-bit encryption ([#1802](https://github.com/docker-mailserver/docker-mailserver/pull/1802)).
- NOTE: This is still very secure but may result in misleading lower scores/grades from security audit websites.
- **[security]** TLS: `TLS_LEVEL=modern` removed support for AES-CBC cipher suites and follows best practices by supporting only AEAD cipher suites ([#1802](https://github.com/docker-mailserver/docker-mailserver/pull/1802)).
- NOTE: As TLS 1.2 is the minimum required for modern already, AEAD cipher suites should already be supported and preferred.
- **[security]** TLS: `TLS_LEVEL=intermediate` has removed support for cipher suites using RSA for key exchange (only available with an RSA certificate) ([#1802](https://github.com/docker-mailserver/docker-mailserver/pull/1802)).
- NOTE: This only affects Dovecot which supported 5 extra cipher suites using AES-CBC and AES-GCM. Your users MUA clients should be unaffected, preferring ECDHE or DHE for key exchange.
- **[refactor]** Complete refactoring of opendkim script ([#1812](https://github.com/docker-mailserver/docker-mailserver/pull/1812)).
- NOTE: Use `./setup.sh config dkim help` to see the new syntax.
The transfer of the old repository to the new organization has completed. This release marks the new starting point for `docker-mailserver` in the `docker-mailserver` organization. Various improvements were made, small bugs fixed and the complete CI was transferred.
- **[general]** transferred the whole repository to `docker-mailserver/docker-mailserver`
- **[general]** adjusted `README.md` and split off `ENVIRONMENT.md`
- **[ci]** usage of the GitHub Container Registry
- **[ci]** switched from TravisCI to **GitHub Actions for CI/CD**
- now building images for `amd64` and `arm/v7` and `arm/64`
