diff --git a/simplenews.module b/simplenews.module
index 93bac4d..ef40151 100644
--- a/simplenews.module
+++ b/simplenews.module
@@ -1400,6 +1400,11 @@ function simplenews_unsubscribe_user($mail, $tid, $confirm = TRUE, $source = 'un
   }
 
   if ($confirm) {
+    // Make sure the mail address is set.
+    if (empty($subscriber)) {
+      $subscriber = new stdClass();
+      $subscriber->mail = $mail;
+    }
     simplenews_confirmation_send('unsubscribe', $subscriber, simplenews_category_load($tid));
   }
   elseif (isset($subscriber->tids[$tid])) {
@@ -2973,7 +2978,7 @@ function simplenews_confirmation_combine($collect = NULL) {
 function simplenews_confirmation_add_combined($action = NULL, $subscriber = NULL, $category = NULL) {
   $group = &drupal_static(__FUNCTION__, array());
   if (!empty($action)) {
-    $group[$subscriber->snid][$category->tid] = $action;
+    $group[$subscriber->mail][$category->tid] = $action;
   }
   else {
     return $group;
@@ -2997,13 +3002,21 @@ function simplenews_confirmation_add_combined($action = NULL, $subscriber = NULL
  *       subscriber received a confirmation.
  */
 function simplenews_confirmation_send_combined() {
+  global $language;
+
   // Disable combining for further confirmations.
   simplenews_confirmation_combine(FALSE);
   $group = simplenews_confirmation_add_combined();
-  foreach ($group as $snid => $changes) {
+  foreach ($group as $mail => $changes) {
     module_load_include('inc', 'simplenews', 'includes/simplenews.mail');
     $params['from'] = _simplenews_set_from();
-    $subscriber = simplenews_subscriber_load($snid);
+    $subscriber = simplenews_subscriber_load_by_mail($mail);
+    if (!$subscriber) {
+      $subscriber = new stdClass();
+      $subscriber->mail = $mail;
+      $subscriber->language = $language->language;
+      $subscriber->tids = array();
+    }
     $params['context']['simplenews_subscriber'] = $subscriber;
     // Send multiple if there is more than one change for this subscriber
     // single otherwise.
@@ -3020,9 +3033,11 @@ function simplenews_confirmation_send_combined() {
       }
     }
 
-    // Save the changes in the subscriber.
-    $subscriber->changes = $changes;
-    simplenews_subscriber_save($subscriber);
+    // Save the changes in the subscriber if there is a real subscriber object.
+    if (!empty($subscriber->snid)) {
+      $subscriber->changes = $changes;
+      simplenews_subscriber_save($subscriber);
+    }
   }
   return !empty($group);
 }
diff --git a/tests/simplenews.test b/tests/simplenews.test
index ed4c25d..4d1a84b 100644
--- a/tests/simplenews.test
+++ b/tests/simplenews.test
@@ -693,6 +693,20 @@ class SimplenewsSubscribeTestCase extends SimplenewsTestCase {
     // Attemt to fetch the page using a wrong hash but correct format.
     $this->drupalGet('newsletter/subscriptions/' . simplenews_generate_hash($subscriber->mail . 'a', $subscriber->snid, $tid));
     $this->assertResponse(404);
+
+    // Attempt to unsubscribe a non-existing subscriber.
+    $mail = $this->randomEmail();
+    $edit = array(
+      'mail' => $mail,
+      'newsletters[' . $tid . ']' => TRUE,
+    );
+    $this->drupalPost('newsletter/subscriptions', $edit, t('Unsubscribe'));
+    $this->assertText(t('You will receive a confirmation e-mail shortly containing further instructions on how to cancel your subscription.'));
+    $mails = $this->drupalGetMails();
+    $body = $mails[8]['body'];
+    // Remove line breaks from body in case the string is split.
+    $body = str_replace("\n", '', $body);
+    $this->assertTrue(strpos($body, 'is not subscribed to this mailing list') !== FALSE);
   }