diff --git a/mod/forum/classes/subscriptions.php b/mod/forum/classes/subscriptions.php
index 74181b6e982..75583df3e2e 100644
--- a/mod/forum/classes/subscriptions.php
+++ b/mod/forum/classes/subscriptions.php
@@ -272,7 +272,7 @@ class subscriptions {
         $sql = "SELECT $fields
                 FROM {user} u
                 JOIN ($esql) je ON je.id = u.id
-               WHERE u.auth <> 'nologin' AND u.suspended = 0
+               WHERE u.auth <> 'nologin' AND u.suspended = 0 AND u.confirmed = 1
             ORDER BY $sort";
 
         return $DB->get_records_sql($sql, $params);
@@ -443,7 +443,7 @@ class subscriptions {
                         ) subscriptions
                         JOIN {user} u ON u.id = subscriptions.userid
                         JOIN ($esql) je ON je.id = u.id
-                        WHERE u.auth <> 'nologin' AND u.suspended = 0
+                        WHERE u.auth <> 'nologin' AND u.suspended = 0 AND u.confirmed = 1
                         ORDER BY u.email ASC";
 
             } else {
@@ -452,7 +452,7 @@ class subscriptions {
                         JOIN ($esql) je ON je.id = u.id
                         JOIN {forum_subscriptions} s ON s.userid = u.id
                         WHERE
-                          s.forum = :forumid AND u.auth <> 'nologin' AND u.suspended = 0
+                          s.forum = :forumid AND u.auth <> 'nologin' AND u.suspended = 0 AND u.confirmed = 1
                         ORDER BY u.email ASC";
             }
             $results = $DB->get_records_sql($sql, $params);
diff --git a/mod/forum/tests/mail_test.php b/mod/forum/tests/mail_test.php
index 4b1654ce868..7688acbf1df 100644
--- a/mod/forum/tests/mail_test.php
+++ b/mod/forum/tests/mail_test.php
@@ -137,6 +137,7 @@ class mod_forum_mail_testcase extends advanced_testcase {
     }
 
     public function test_forced_subscription() {
+        global $DB;
         $this->resetAfterTest(true);
 
         // Create a course, with a forum.
@@ -145,8 +146,14 @@ class mod_forum_mail_testcase extends advanced_testcase {
         $options = array('course' => $course->id, 'forcesubscribe' => FORUM_FORCESUBSCRIBE);
         $forum = $this->getDataGenerator()->create_module('forum', $options);
 
-        // Create two users enrolled in the course as students.
-        list($author, $recipient) = $this->helper_create_users($course, 2);
+        // Create users enrolled in the course as students.
+        list($author, $recipient, $unconfirmed, $deleted) = $this->helper_create_users($course, 4);
+
+        // Make the third user unconfirmed (thence inactive) to make sure it does not break the notifications.
+        $DB->set_field('user', 'confirmed', 0, ['id' => $unconfirmed->id]);
+
+        // Mark the fourth user as deleted to make sure it does not break the notifications.
+        $DB->set_field('user', 'deleted', 1, ['id' => $deleted->id]);
 
         // Post a discussion to the forum.
         list($discussion, $post) = $this->helper_post_to_forum($forum, $author);
@@ -160,11 +167,21 @@ class mod_forum_mail_testcase extends advanced_testcase {
                 'userid' => $recipient->id,
                 'messages' => 1,
             ],
+            (object) [
+                'userid' => $unconfirmed->id,
+                'messages' => 0,
+            ],
+            (object) [
+                'userid' => $deleted->id,
+                'messages' => 0,
+            ],
         ];
         $this->queue_tasks_and_assert($expect);
 
         $this->send_notifications_and_assert($author, [$post]);
         $this->send_notifications_and_assert($recipient, [$post]);
+        $this->send_notifications_and_assert($unconfirmed, []);
+        $this->send_notifications_and_assert($deleted, []);
     }
 
     /**