diff --git a/config/schema/inmail.schema.yml b/config/schema/inmail.schema.yml
index 187f676..f2d0a70 100644
--- a/config/schema/inmail.schema.yml
+++ b/config/schema/inmail.schema.yml
@@ -110,3 +110,12 @@ inmail.plugin.deliverer.imap:
     batch_size:
       label: 'Batch size'
       type: integer
+
+# Schema for IMAP quota sensor.
+monitoring.settings.inmail_monitoring_imap_quota:
+  type: monitoring.settings_base
+  label: 'IMAP quota sensor settings'
+  mapping:
+    imap_fetcher:
+      label: Inmail IMAP fetcher to track its quota
+      type: string
diff --git a/inmail.info.yml b/inmail.info.yml
index 273f9c5..3e0733f 100644
--- a/inmail.info.yml
+++ b/inmail.info.yml
@@ -4,5 +4,9 @@ description: Incoming mail message handler. Fetches and processes incoming mail
 package: Mail
 version: 8.x-1.x
 core: 8.x
+
+dependencies:
+  - monitoring
+
 test_dependencies:
   - past
diff --git a/inmail_monitoring/config/schema/inmail_monitoring.schema.yml b/inmail_monitoring/config/schema/inmail_monitoring.schema.yml
deleted file mode 100644
index e7e3eac..0000000
--- a/inmail_monitoring/config/schema/inmail_monitoring.schema.yml
+++ /dev/null
@@ -1,8 +0,0 @@
-# Schema for IMAP quota sensor.
-monitoring.settings.inmail_monitoring_imap_quota:
-  type: monitoring.settings_base
-  label: 'IMAP quota sensor settings'
-  mapping:
-    imap_fetcher:
-      label: Inmail IMAP fetcher to track its quota
-      type: string
diff --git a/inmail_monitoring/inmail_monitoring.info.yml b/inmail_monitoring/inmail_monitoring.info.yml
deleted file mode 100644
index a988931..0000000
--- a/inmail_monitoring/inmail_monitoring.info.yml
+++ /dev/null
@@ -1,10 +0,0 @@
-name: Inmail Monitoring
-type: module
-description: Monitors the state of Inmail module.
-package: Mail
-version: 8.x-1.x
-core: 8.x
-
-dependencies:
-  - inmail
-  - monitoring
diff --git a/inmail_monitoring/src/Plugin/monitoring/SensorPlugin/IMAPQuotaSensorPlugin.php b/src/Plugin/monitoring/SensorPlugin/IMAPQuotaSensorPlugin.php
similarity index 80%
rename from inmail_monitoring/src/Plugin/monitoring/SensorPlugin/IMAPQuotaSensorPlugin.php
rename to src/Plugin/monitoring/SensorPlugin/IMAPQuotaSensorPlugin.php
index 1b3260e..efa8aec 100644
--- a/inmail_monitoring/src/Plugin/monitoring/SensorPlugin/IMAPQuotaSensorPlugin.php
+++ b/src/Plugin/monitoring/SensorPlugin/IMAPQuotaSensorPlugin.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Drupal\inmail_monitoring\Plugin\monitoring\SensorPlugin;
+namespace Drupal\inmail\Plugin\monitoring\SensorPlugin;
 
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\inmail\Entity\DelivererConfig;
@@ -15,7 +15,7 @@ use Drupal\monitoring\SensorPlugin\SensorPluginBase;
  *   id = "inmail_monitoring_imap_quota",
  *   label = @Translation("Inmail IMAP Quota"),
  *   description = @Translation("Monitors IMAP quota of Inmail fetchers."),
- *   addable = FALSE
+ *   addable = TRUE
  * )
  */
 class IMAPQuotaSensorPlugin extends SensorPluginBase {
@@ -44,13 +44,21 @@ class IMAPQuotaSensorPlugin extends SensorPluginBase {
       }
     }
 
+    $has_fetchers = (bool) $imap_fetchers;
     $form['imap_fetcher'] = array(
-      '#type' => 'radios',
+      '#type' => 'select',
       '#options' => $imap_fetchers,
       '#title' => t('IMAP Fetchers'),
       '#description' => t('Select a fetcher to track its IMAP quota.'),
       '#default_value' => $this->sensorConfig->getSetting('imap_fetcher'),
+      '#access' => $has_fetchers,
     );
+    if (!$has_fetchers) {
+      $form['imap_fetcher_add'] = array(
+        '#type' => 'item',
+        '#title' => t('There are no IMAP fetchers. Please <a href=":url">add</a> one.', array(':url' => '/admin/config/system/inmail/deliverers/add')),
+      );
+    }
 
     return $form;
   }
@@ -78,18 +86,19 @@ class IMAPQuotaSensorPlugin extends SensorPluginBase {
     if ($quota = $plugin->getQuota()) {
       $usage = $quota['STORAGE']['usage'];
       $limit = $quota['STORAGE']['limit'];
+      $percentage = round($usage/$limit * 100);
       if ($usage >= $limit) {
         $result->setStatus(SensorResultInterface::STATUS_CRITICAL);
       }
       else {
         $result->setStatus(SensorResultInterface::STATUS_OK);
       }
-      $result->setValue($usage);
-      $result->setMessage('The usage quota for @imap_fetcher is @usage KB and the limit is @limit KB', ['@imap_fetcher' => $imap_fetcher->id(), '@usage' => $usage, '@limit' => $limit]);
+      $result->setValue($percentage);
+      $result->addStatusMessage('@fetcher usage quota: @usage/@limit KB.', ['@fetcher' => $imap_fetcher->id(), '@usage' => $usage, '@limit' => $limit]);
     }
     else {
       $result->setStatus(SensorResultInterface::STATUS_UNKNOWN);
-      $result->setMessage('No quota information for @imap_fetcher fetcher.', ['@imap_fetcher' => $imap_fetcher->id()]);
+      $result->addStatusMessage('No quota information for @fetcher fetcher.', ['@fetcher' => $imap_fetcher->id()]);
     }
   }
 }