diff --git a/web/modules/custom/yufu_admin/README.md b/web/modules/custom/yufu_admin/README.md
new file mode 100644
index 0000000..acd912b
--- /dev/null
+++ b/web/modules/custom/yufu_admin/README.md
@@ -0,0 +1,12 @@
+# Yufu Admin
+
+Administrativna in uredniška funkcionalnost.
+
+Obveščanje preko mailov, ko se spremeni revizija koncepta.
+
+## Testiranje
+
+1. Kot anonimni uporabnik predlagamo spremembe koncepta preko frontend apija.
+2. Kot urednik objavimo predlagane spremembe.
+   - Fino bi bilo imet pregled (view) predlaganih in še ne objavljenih sprememb.
+3. Pogledamo v mailhog, če so se maili poslali. (ddev status)
diff --git a/web/modules/custom/yufu_admin/translations/yufu_admin.sl.po b/web/modules/custom/yufu_admin/translations/yufu_admin.sl.po
new file mode 100644
index 0000000..b9ad7e0
--- /dev/null
+++ b/web/modules/custom/yufu_admin/translations/yufu_admin.sl.po
@@ -0,0 +1,4 @@
+# Slovenian translations for yufu_admin module
+#
+msgid "There was a problem sending your message and it was not sent. For transition @transition."
+msgstr "Prišlo je do problema pri pošiljanju e-poštnega sporočila in le to ni bilo poslano. Za tranzicijo @transition"
diff --git a/web/modules/custom/yufu_admin/yufu_admin.module b/web/modules/custom/yufu_admin/yufu_admin.module
index 7d7b030..edbd3f3 100644
--- a/web/modules/custom/yufu_admin/yufu_admin.module
+++ b/web/modules/custom/yufu_admin/yufu_admin.module
@@ -15,7 +15,7 @@ use Drupal\node\NodeInterface;
 function yufu_admin_entity_operation(EntityInterface $entity) {
   $operations = [];
   $entityType = $entity->getEntityType();
-  // @todo Only for entity node - should we add other entities as well?
+  // @TODO Only for entity node - should we add other entities as well?
   if ($entityType->id() === 'node' && \Drupal::currentUser()->hasPermission('use jsonapi operation link')) {
     // Build the url.
     $url = Url::fromRoute(sprintf('jsonapi.%s--%s.individual', $entityType->id(), $entity->bundle()),
@@ -67,12 +67,15 @@ function yufu_admin_node_presave(EntityInterface $entity) {
       $transition = _yufu_admin_get_node_transition($entity);
     }
     switch ($transition) {
+      case 'stay_draft':
       case 'concept_drafted':
         // Send email to editors.
         _yufu_admin_concept_drafted_mail($entity);
         break;
       case 'concept_approved':
         // Send email to revision creator (user).
+        // @TODO Maybe notify other editors.
+        _yufu_admin_concept_approved_send_mail($entity);
         break;
       case 'concept_rejectd':
         // Send email to revision creator (user).
@@ -93,10 +96,10 @@ function yufu_admin_node_presave(EntityInterface $entity) {
  *   Name of the transition.
  */
 function _yufu_admin_get_node_transition(NodeInterface $node) {
-  $original = $node->original;
+  $original = $node->original ?? NULL;
   $moderation_state = $node->moderation_state->value;
-  $previous_state = $original->moderation_state->value;
-  if ($moderation_state == 'draft' && $previous_state == 'published') {
+  $previous_state = $original?->moderation_state->value ?? NULL;
+  if ($moderation_state == 'draft' && in_array($previous_state, ['published', NULL])) {
     return 'concept_drafted';
   }
   else if ($moderation_state == 'published' && $previous_state == 'draft') {
@@ -111,34 +114,55 @@ function _yufu_admin_get_node_transition(NodeInterface $node) {
   return NULL;
 }
 
+/**
+ * Notify user that their concept (revision) was published.
+ *
+ * @param \Drupal\node\NodeInterface $node
+ *   Concept node that was transitioned into published state.
+ */
 function _yufu_admin_concept_drafted_mail(NodeInterface $node) {
   $mailManager = \Drupal::service('plugin.manager.mail');
   $module = 'yufu_admin';
+  // @TODO - key doesn't need to be defined again.
   $key = 'concept_drafted';
   // To all editors.
   $to = _yufu_admin_get_all_editors_emails();
   $params['message'] = t('New concept created: @title - @url', [
-    'title' => $node->getTitle(),
-    'url' => $node->toUrl()->toString(),
+    '@title' => $node->getTitle(),
+    '@url' => $node->toUrl()->toString(),
   ]);
-  $params['node_title'] = $entity->label();
+  $params['node_title'] = $node->getTitle();
   $langcode = \Drupal::currentUser()->getPreferredLangcode();
   $send = true;
 
   $result = $mailManager->mail($module, $key, $to, $langcode, $params, NULL, $send);
+  // @TODO: Remove code duplications (_yufu_admin_concept_approved_send_mail).
   if ($result['result'] !== true) {
-    drupal_set_message(t('There was a problem sending your message and it was not sent.'), 'error');
+    Drupal::logger('yufu_admin')->error(t('There was a problem sending your message and it was not sent. For transition @transition.', [
+      '@transition' => $key,
+    ]), 'error');
+    Drupal::messenger()->addError(t('There was a problem sending your message and it was not sent. For transition @transition.', [
+      '@transition' => $key,
+    ]), 'error');
   }
   else {
-    drupal_set_message(t('Your message has been sent.'));
+    Drupal::logger('yufu_admin')->notice(t('Your message has been sent.'));
+    Drupal::messenger()->addStatus(t('Your message has been sent.'));
   }
 }
 
+/**
+ * Get a list of emails of all editors.
+ *
+ * @return array
+ *   List of strings.
+ */
 function _yufu_admin_get_all_editors_emails() {
   $user_storage = \Drupal::entityTypeManager()->getStorage('user');
   $ids = $user_storage->getQuery()
     ->condition('status', 1)
     ->condition('roles', 'administrator')
+    ->accessCheck(FALSE)
     ->execute();
   $editors = $user_storage->loadMultiple($ids);
   $emails = [];
@@ -148,3 +172,80 @@ function _yufu_admin_get_all_editors_emails() {
   }
   return $emails;
 }
+
+/**
+ * Notify user that their concept (revision) was published.
+ *
+ * @param \Drupal\node\NodeInterface $node
+ *   Concept node that was transitioned into published state.
+ */
+function _yufu_admin_concept_approved_send_mail(NodeInterface $node) {
+  $mailManager = \Drupal::service('plugin.manager.mail');
+  $module = 'yufu_admin';
+  // @TODO - key doesn't need to be defined again.
+  $key = 'concept_approved';
+  // To the revision's authors.
+  // @TODO - to make this work properly, we should get a list of all authors of
+  // unpublished revisions so far since the last published revision.
+  if ($to = _yufu_admin_get_pioneer_email($node)) {
+    $params['message'] = t('New concept created: @title - @url', [
+      '@title' => $node->getTitle(),
+      '@url' => $node->toUrl()->toString(),
+    ]);
+  }
+  else {
+    $to = implode(',', _yufu_admin_get_all_editors_emails());
+    $params['message'] = t('Published changes not attributed to any of knownn users: @title - @url', [
+      'title' => $node->getTitle(),
+      'url' => $node->toUrl()->toString(),
+    ]);
+  }
+  $params['node_title'] = $node->getTitle();
+  $langcode = \Drupal::currentUser()->getPreferredLangcode();
+  $send = TRUE;
+
+  $result = $mailManager->mail($module, $key, $to, $langcode, $params, NULL, $send);
+  if ($result['result'] !== TRUE) {
+    Drupal::logger('yufu_admin')->error(t('There was a problem sending your message and it was not sent. For transition @transition.', [
+      '@transition' => $key,
+    ]), 'error');
+    Drupal::messenger()->addError(t('There was a problem sending your message and it was not sent. For transition @transition.', [
+      '@transition' => $key,
+    ]), 'error');
+  }
+  else {
+    Drupal::logger('yufu_admin')->notice(t('Your message has been sent.'));
+    Drupal::messenger()->addStatus(t('Your message has been sent.'));
+  }
+}
+
+/**
+ * Get the email of person (pioneer) that worked on proposed changes.
+ *
+ * @return string|NULL
+ *   List of strings.
+ */
+function _yufu_admin_get_pioneer_email(NodeInterface $node) {
+  // $email = $node->uid->entity;
+  if ($original = $node->original) {
+    $user = $original->getRevisionUser();
+    $email = $user->getEmail();
+    return $email ?? NULL;
+  }
+  // @TODO: Make this code nicer.
+  $user = $node->getRevisionUser();
+  $email = $user->getEmail();
+  return $email ?? NULL;
+}
+
+
+/**
+ * Get a list of emails of people that worked on proposed changes.
+ *
+ * @return array
+ *   List of strings.
+ */
+function _yufu_admin_get_all_pioneer_emails() {
+  // @TODO: Think it through if it is really needed.
+  return [];
+}