Merge branch 'features' into 'master'

README: Update existing and future features

See merge request simple-nixos-mailserver/nixos-mailserver!376

README.md

@@ -53,6 +53,7 @@ can stay up to date with bug fixes and updates.
  * User Management
     - [x] declarative user management
     - [x] declarative password management
+    - [x] LDAP users
  * Sieves
     - [x] A simple standard script that moves spam
     - [x] Allow user defined sieve scripts
@@ -64,7 +65,15 @@ can stay up to date with bug fixes and updates.
 ### In the future
 
   * DKIM Signing
-    - [ ] Allow a per domain selector
+    - [ ] Allow per domain selectors
+    - [ ] Allow passing DKIM signing keys
+  * Improve the Forwarding Experience
+    - [ ] Support [ARC](https://en.wikipedia.org/wiki/Authenticated_Received_Chain) signing with [Rspamd](https://rspamd.com/doc/modules/arc.html)
+    - [ ] Support [SRS](https://en.wikipedia.org/wiki/Sender_Rewriting_Scheme) with [postsrsd](https://github.com/roehling/postsrsd)
+  * User management
+    - [ ] Allow local and LDAP user to coexist
+  * OpenID Connect
+    - Depends on relevant clients adding support, e.g. [Thunderbird](https://bugzilla.mozilla.org/show_bug.cgi?id=1602166)
 
 ### Get in touch