diff --git a/includes/simplenews.source.inc b/includes/simplenews.source.inc
index ab4897b..1440a47 100644
--- a/includes/simplenews.source.inc
+++ b/includes/simplenews.source.inc
@@ -298,6 +298,16 @@ class SimplenewsSpool implements SimplenewsSpoolInterface {
       $subscriber = simplenews_subscriber_load_by_mail($spool_data->mail);
     }
 
+    if (!$subscriber) {
+      // If loading the subscriber failed, set the processed status done and
+      // proceed with the next mail.
+      $this->processed[$spool_data->msid]->result = array(
+        'status' => SIMPLENEWS_SPOOL_DONE,
+        'error' => TRUE
+      );
+      return $this->nextSource();
+    }
+
     $source_class = $this->getSourceImplementation($spool_data);
     $source = new $source_class($node, $subscriber);
 
diff --git a/tests/simplenews.test b/tests/simplenews.test
index c5bd3ce..c0eb6a6 100644
--- a/tests/simplenews.test
+++ b/tests/simplenews.test
@@ -2892,6 +2892,36 @@ class SimplenewsSourceTestCase extends SimplenewsTestCase {
     $spool_row = db_query('SELECT * FROM {simplenews_mail_spool}')->fetchObject();
     $this->assertEqual(SIMPLENEWS_SPOOL_DONE, $spool_row->status);
   }
+
+  /**
+   * Test with disabled caching.
+   */
+  function testSendMissingSubscriber() {
+    $this->setUpSubscribers(1);
+
+    $edit = array(
+      'title' => $this->randomName(),
+      'body[und][0][value]' => "Mail token: <strong>[simplenews-subscriber:mail]</strong>",
+    );
+    $this->drupalPost('node/add/simplenews', $edit, ('Save'));
+    $this->assertTrue(preg_match('|node/(\d+)$|', $this->getUrl(), $matches), 'Node created');
+    $node = node_load($matches[1]);
+
+    // Add node to spool.
+    simplenews_add_node_to_spool($node);
+
+    // Delete the subscriber.
+    $subscriber = simplenews_subscriber_load_by_mail(reset($this->subscribers));
+    simplenews_subscriber_delete($subscriber);
+
+    simplenews_mail_spool();
+
+    // Make sure that no mails have been sent.
+    $this->assertEqual(0, count($this->drupalGetMails()));
+
+    $spool_row = db_query('SELECT * FROM {simplenews_mail_spool}')->fetchObject();
+    $this->assertEqual(SIMPLENEWS_SPOOL_DONE, $spool_row->status);
+  }
 }
 
 /**