fix: `start-mailserver.sh` requires `mail_state.sh` to be sourced on restarts

target/scripts/start-mailserver.sh

@@ -181,6 +181,9 @@ if [[ -f /CONTAINER_START ]]; then
   # We cannot skip all setup routines because some need to run _after_
   # the initial setup (and hence, they cannot be moved to the check stack).
   _setup_directory_and_file_permissions
+
+  # shellcheck source=./startup/setup.d/mail_state.sh
+  source /usr/local/bin/setup.d/mail_state.sh
   _setup_adjust_state_permissions
 else
   _setup