diff --git a/inmail.install b/inmail.install
index bb72393..51c6b94 100644
--- a/inmail.install
+++ b/inmail.install
@@ -3,6 +3,7 @@
  * @file
  * Implementations of install hooks for the Inmail module.
  */
+use Drupal\Core\Url;
 
 /**
  * Implements hook_requirements().
@@ -45,7 +46,19 @@ function inmail_get_requirements() {
         $requirements[$entity_key] = $plugin->checkInstanceRequirements();
         // Add title in case requirements are not empty.
         if (!empty($requirements[$entity_key])) {
-          $requirements[$entity_key]['title'] = $entity->label() . ' (' . $entity->id() . ')';
+          $requirements[$entity_key]['title'] = t('Inmail @plugin_label: @entity_label', [
+              '@plugin_label' => $plugin->getPluginDefinition()['label'],
+              '@entity_label' => $entity->label(),
+            ]
+          );
+
+          $url = Url::fromRoute('entity.inmail_deliverer.edit_form',
+             ['inmail_deliverer' => $entity->id(),])->toString();
+          $requirements[$entity_key]['description'] = t('@old_description Configure the <a href=":url">plugin instance</a>.', [
+            '@old_description' => $requirements[$entity_key]['description'],
+            ':url' => $url,
+            ]
+          );
         }
 
         // Check plugin requirements only if it is not already checked.
@@ -56,7 +69,7 @@ function inmail_get_requirements() {
       catch (\Drupal\Component\Plugin\Exception\PluginException $e) {
         $requirements[$plugin_key] = [
           'title' => t('Missing plugin @id', ['@id' => $plugin_id]),
-          'description' => t('Inmail @type plugin @id is missing and cannot be used.', ['@type' => $plugin_type, '@id' => $plugin_id]),
+          'description' => t('Inmail @type plugin @id is missing and cannot be used.', ['@type' => $plugin_type, '@id' => $plugin_id,]),
           'severity' => REQUIREMENT_ERROR,
         ];
       }
diff --git a/src/Plugin/inmail/Deliverer/ImapFetcher.php b/src/Plugin/inmail/Deliverer/ImapFetcher.php
index d37f847..bfd7c11 100644
--- a/src/Plugin/inmail/Deliverer/ImapFetcher.php
+++ b/src/Plugin/inmail/Deliverer/ImapFetcher.php
@@ -121,13 +121,8 @@ class ImapFetcher extends FetcherBase implements ContainerFactoryPluginInterface
    */
   protected function doImap(callable $callback) {
     // Connect to IMAP with details from configuration.
-    $mailbox = '{'. $this->configuration['host'] . ':' . $this->configuration['port'] . $this->getFlags() . '}';
+    $imap_res = $this->doImapOpen();
 
-    $imap_res = @imap_open(
-      $mailbox,
-      $this->configuration['username'],
-      $this->configuration['password']
-    );
     $errors = imap_errors();
     if (empty($imap_res)) {
       // @todo Return noisily if misconfigured or imap missing. Possibly stop retrying, https://www.drupal.org/node/2405757
@@ -144,6 +139,30 @@ class ImapFetcher extends FetcherBase implements ContainerFactoryPluginInterface
   }
 
   /**
+   * Run imap_open() and return result.
+   *
+   * @return resource
+   *   The IMAP resource.
+   */
+  public function doImapOpen() {
+    return @imap_open(
+      $this->getMailbox(),
+      $this->getConfiguration()['username'],
+      $this->getConfiguration()['password']
+    );
+  }
+
+  /**
+   * Returns the mailbox.
+   *
+   * @return string
+   *   The mailbox for deliverer.
+   */
+  public function getMailbox() {
+    return '{' . $this->configuration['host'] . ':' . $this->configuration['port'] . $this->getFlags() . '}';
+  }
+
+  /**
    * Return the flags for mailbox.
    *
    * @return string
@@ -351,6 +370,36 @@ class ImapFetcher extends FetcherBase implements ContainerFactoryPluginInterface
   /**
    * {@inheritdoc}
    */
+  public function checkInstanceRequirements() {
+    $requirements = [
+      'status' => REQUIREMENT_OK,
+    ];
+    if ($this->isAvailable()) {
+      if (!$this->doImapOpen()) {
+        $requirements['description'] = $this->t(
+          'Deliverer connection failed: @error.',
+          ['@error' => implode(' ', imap_errors())]
+        );
+        $requirements['severity'] = REQUIREMENT_ERROR;
+      }
+      else {
+        $requirements['description'] = $this->t('Connection successful.');
+      }
+    }
+    else {
+      $requirements['description'] = $this->t(
+        'The <a href=":imap">PHP IMAP</a> extension is missing, it must be enabled.',
+        [':imap' => 'http://www.php.net/imap']
+      );
+      $requirements['severity'] = REQUIREMENT_WARNING;
+    }
+
+    return $requirements;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function isAvailable() {
     // Checks if the imap extension is enabled.
     return function_exists('imap_open');
diff --git a/tests/src/Kernel/ProcessorTest.php b/tests/src/Kernel/ProcessorTest.php
index e2aec76..e5eb416 100644
--- a/tests/src/Kernel/ProcessorTest.php
+++ b/tests/src/Kernel/ProcessorTest.php
@@ -35,7 +35,7 @@ class ProcessorTest extends KernelTestBase {
     $processor = \Drupal::service('inmail.processor');
     $path = drupal_get_path('module', 'inmail_test') . '/eml/malformed/headerbody.eml';
     $raw = file_get_contents(DRUPAL_ROOT . '/' . $path);
-    $processor->process($raw, DelivererConfig::create(array('id' => 'test')));
+    $processor->process($raw, DelivererConfig::create(['id' => 'test']));
 
     // Check last DbLog message.
     $dblog_statement = \Drupal::database()->select('watchdog', 'w')
@@ -66,7 +66,7 @@ EOF;
     // Add an unavailable analyzer.
     $unavailable_analyzer = AnalyzerConfig::create([
       'id' => 'unavailable_analyzer',
-      'label' => 'Unavailable Analyzer',
+      'label' => 'Unavailable analyzer instance',
       'plugin' => 'unavailable_analyzer',
     ]);
     $unavailable_analyzer->save();
@@ -98,6 +98,13 @@ EOF;
     // The body message has not changed. It implies UnavailableAnalyzer
     // did not run.
     $this->assertEquals('Hello world!', $default_result->getBody());
+
+    module_load_install('inmail');
+    $requirements = inmail_get_requirements();
+    $this->assertEquals(
+      $requirements['analyzer_entity_unavailable_analyzer']['title'],
+      'Inmail Unavailable Analyzer: Unavailable analyzer instance'
+    );
   }
 
 }