diff --git a/badges/tests/badgeslib_test.php b/badges/tests/badgeslib_test.php
index a5715695899..1ed3a1b8443 100644
--- a/badges/tests/badgeslib_test.php
+++ b/badges/tests/badgeslib_test.php
@@ -29,7 +29,7 @@ defined('MOODLE_INTERNAL') || die();
 global $CFG;
 require_once($CFG->libdir . '/badgeslib.php');
 
-class core_badgeslib_testcase extends advanced_testcase {
+class core_badges_badgeslib_testcase extends advanced_testcase {
     protected $badgeid;
     protected $course;
     protected $user;
@@ -41,6 +41,8 @@ class core_badgeslib_testcase extends advanced_testcase {
         global $DB, $CFG;
         $this->resetAfterTest(true);
 
+        unset_config('noemailever');
+
         $user = $this->getDataGenerator()->create_user();
 
         $fordb = new stdClass();
@@ -239,7 +241,10 @@ class core_badgeslib_testcase extends advanced_testcase {
         $current = $c->get_data($activities[$this->module->cmid], false, $this->user->id);
         $current->completionstate = COMPLETION_COMPLETE;
         $current->timemodified = time();
+        $sink = $this->redirectEmails();
         $c->internal_set_data($activities[$this->module->cmid], $current);
+        $this->assertCount(1, $sink->get_messages());
+        $sink->close();
 
         // Check if badge is awarded.
         $this->assertDebuggingCalled('Error baking badge image!');
@@ -261,7 +266,10 @@ class core_badgeslib_testcase extends advanced_testcase {
         $ccompletion = new completion_completion(array('course' => $this->course->id, 'userid' => $this->user->id));
 
         // Mark course as complete.
+        $sink = $this->redirectEmails();
         $ccompletion->mark_complete();
+        $this->assertCount(1, $sink->get_messages());
+        $sink->close();
 
         // Check if badge is awarded.
         $this->assertDebuggingCalled('Error baking badge image!');
@@ -281,7 +289,10 @@ class core_badgeslib_testcase extends advanced_testcase {
         $criteria_overall1->save(array('agg' => BADGE_CRITERIA_AGGREGATION_ALL, 'field_address' => 'address'));
 
         $this->user->address = 'Test address';
+        $sink = $this->redirectEmails();
         user_update_user($this->user, false);
+        $this->assertCount(1, $sink->get_messages());
+        $sink->close();
         // Check if badge is awarded.
         $this->assertDebuggingCalled('Error baking badge image!');
         $this->assertTrue($badge->is_issued($this->user->id));
@@ -300,7 +311,10 @@ class core_badgeslib_testcase extends advanced_testcase {
         $criteria_overall1->save(array('agg' => BADGE_CRITERIA_AGGREGATION_ALL, 'field_address' => 'address'));
 
         $this->user->address = 'Test address';
+        $sink = $this->redirectEmails();
         user_update_user($this->user, false);
+        $this->assertCount(1, $sink->get_messages());
+        $sink->close();
         // Check if badge is awarded.
         $this->assertDebuggingCalled('Error baking badge image!');
         $awards = $badge->get_awards();
diff --git a/course/tests/courserequest_test.php b/course/tests/courserequest_test.php
index 0b23a4eabb8..3b85c334ae6 100644
--- a/course/tests/courserequest_test.php
+++ b/course/tests/courserequest_test.php
@@ -81,7 +81,8 @@ class core_course_courserequest_testcase extends advanced_testcase {
         $this->resetAfterTest(true);
         $this->preventResetByRollback();
 
-        $this->setAdminUser();
+        unset_config('noemailever');
+
         $defaultcategory = $DB->get_field_select('course_categories', "MIN(id)", "parent=0");
         set_config('enablecourserequests', 1);
         set_config('requestcategoryselection', 0);
@@ -91,6 +92,8 @@ class core_course_courserequest_testcase extends advanced_testcase {
         $cat1 = $this->getDataGenerator()->create_category();
         $cat2 = $this->getDataGenerator()->create_category();
 
+        $requester = $this->getDataGenerator()->create_user();
+
         $data = new stdClass();
         $data->fullname = 'Həllo World!';
         $data->shortname = 'Hi th€re!';
@@ -99,9 +102,13 @@ class core_course_courserequest_testcase extends advanced_testcase {
         $data->reason = 'Because PHP Unit is cool.';
 
         // Test without category.
+        $this->setUser($requester);
         $cr = course_request::create($data);
+        $this->setAdminUser();
+        $sink = $this->redirectMessages();
         $id = $cr->approve();
-        $this->assertDebuggingCalled(); // Caused by sending of message.
+        $this->assertCount(1, $sink->get_messages());
+        $sink->close();
         $course = $DB->get_record('course', array('id' => $id));
         $this->assertEquals($data->fullname, $course->fullname);
         $this->assertEquals($data->shortname, $course->shortname);
@@ -115,9 +122,13 @@ class core_course_courserequest_testcase extends advanced_testcase {
         set_config('defaultrequestcategory', $cat2->id);
         $data->shortname .= ' 2nd';
         $data->category = $cat1->id;
+        $this->setUser($requester);
         $cr = course_request::create($data);
+        $this->setAdminUser();
+        $sink = $this->redirectMessages();
         $id = $cr->approve();
-        $this->assertDebuggingCalled(); // Caused by sending of message.
+        $this->assertCount(1, $sink->get_messages());
+        $sink->close();
         $course = $DB->get_record('course', array('id' => $id));
         $this->assertEquals($data->category, $course->category);
     }
@@ -126,11 +137,16 @@ class core_course_courserequest_testcase extends advanced_testcase {
         global $DB;
         $this->resetAfterTest(true);
         $this->preventResetByRollback();
+
+        unset_config('noemailever');
+
         $this->setAdminUser();
         set_config('enablecourserequests', 1);
         set_config('requestcategoryselection', 0);
         set_config('defaultrequestcategory', $DB->get_field_select('course_categories', "MIN(id)", "parent=0"));
 
+        $requester = $this->getDataGenerator()->create_user();
+
         $data = new stdClass();
         $data->fullname = 'Həllo World!';
         $data->shortname = 'Hi th€re!';
@@ -138,11 +154,15 @@ class core_course_courserequest_testcase extends advanced_testcase {
         $data->summary_editor['format'] = FORMAT_HTML;
         $data->reason = 'Because PHP Unit is cool.';
 
+        $this->setUser($requester);
         $cr = course_request::create($data);
         $this->assertTrue($DB->record_exists('course_request', array('id' => $cr->id)));
-        $cr->reject('Sorry!');
-        $this->assertDebuggingCalled(); // Caused by sending of message.
-        $this->assertFalse($DB->record_exists('course_request', array('id' => $cr->id)));
-    }
 
+        $this->setAdminUser();
+        $sink = $this->redirectMessages();
+        $cr->reject('Sorry!');
+        $this->assertFalse($DB->record_exists('course_request', array('id' => $cr->id)));
+        $this->assertCount(1, $sink->get_messages());
+        $sink->close();
+    }
 }
diff --git a/lib/badgeslib.php b/lib/badgeslib.php
index 815fb2acfee..26d44478fb9 100644
--- a/lib/badgeslib.php
+++ b/lib/badgeslib.php
@@ -411,9 +411,7 @@ class badge {
                 $pathhash = badges_bake($issued->uniquehash, $this->id, $userid, true);
 
                 // Notify recipients and badge creators.
-                if (empty($CFG->noemailever)) {
-                    badges_notify_badge_award($this, $userid, $issued->uniquehash, $pathhash);
-                }
+                badges_notify_badge_award($this, $userid, $issued->uniquehash, $pathhash);
             }
         }
     }
@@ -634,7 +632,9 @@ function badges_notify_badge_award(badge $badge, $userid, $issued, $filepathhash
     $message = badge_message_from_template($badge->message, $params);
     $plaintext = format_text_email($message, FORMAT_HTML);
 
-    if ($badge->attachment && $filepathhash) {
+    // TODO: $filepathhash may be moodle_url instance too...
+
+    if ($badge->attachment && is_string($filepathhash)) {
         $fs = get_file_storage();
         $file = $fs->get_file_by_hash($filepathhash);
         $attachment = $file->copy_content_to_temp();
diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index 27ee39ba6d9..cf389e09c0f 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -5605,32 +5605,24 @@ function email_to_user($user, $from, $subject, $messagetext, $messagehtml = '',
 
     global $CFG;
 
-    if (empty($user) || empty($user->email)) {
-        $nulluser = 'User is null or has no email';
-        error_log($nulluser);
-        if (CLI_SCRIPT) {
-            mtrace('Error: lib/moodlelib.php email_to_user(): '.$nulluser);
-        }
+    if (empty($user) or empty($user->id)) {
+        debugging('Can not send email to null user', DEBUG_DEVELOPER);
+        return false;
+    }
+
+    if (empty($user->email)) {
+        debugging('Can not send email to user without email: '.$user->id, DEBUG_DEVELOPER);
         return false;
     }
 
     if (!empty($user->deleted)) {
-        // Do not mail deleted users.
-        $userdeleted = 'User is deleted';
-        error_log($userdeleted);
-        if (CLI_SCRIPT) {
-            mtrace('Error: lib/moodlelib.php email_to_user(): '.$userdeleted);
-        }
+        debugging('Can not send email to deleted user: '.$user->id, DEBUG_DEVELOPER);
         return false;
     }
 
     if (!empty($CFG->noemailever)) {
         // Hidden setting for development sites, set in config.php if needed.
-        $noemail = 'Not sending email due to noemailever config setting';
-        error_log($noemail);
-        if (CLI_SCRIPT) {
-            mtrace('Error: lib/moodlelib.php email_to_user(): '.$noemail);
-        }
+        debugging('Not sending email due to $CFG->noemailever config setting', DEBUG_NORMAL);
         return true;
     }
 
diff --git a/lib/phpmailer/moodle_phpmailer.php b/lib/phpmailer/moodle_phpmailer.php
index 881b1f8126d..d58da430415 100644
--- a/lib/phpmailer/moodle_phpmailer.php
+++ b/lib/phpmailer/moodle_phpmailer.php
@@ -147,7 +147,7 @@ class moodle_phpmailer extends PHPMailer {
         // Now ask phpunit if it wants to catch this message.
         if (PHPUNIT_TEST) {
             if (!phpunit_util::is_redirecting_phpmailer()) {
-                debugging('Unit tests must not send real emails! Use $this->start_phpmailer_redirection()');
+                debugging('Unit tests must not send real emails! Use $this->redirectEmails()');
                 return true;
             }
             $mail = new stdClass();
diff --git a/lib/tests/authlib_test.php b/lib/tests/authlib_test.php
index 2abcd82d96e..6d1e1e55088 100644
--- a/lib/tests/authlib_test.php
+++ b/lib/tests/authlib_test.php
@@ -36,8 +36,7 @@ class core_authlib_testcase extends advanced_testcase {
 
         $this->resetAfterTest();
 
-        $oldlog = ini_get('error_log');
-        ini_set('error_log', "$CFG->dataroot/testlog.log"); // Prevent standard logging.
+        unset_config('noemailever');
 
         set_config('lockoutthreshold', 0);
         set_config('lockoutwindow', 60*20);
@@ -60,10 +59,10 @@ class core_authlib_testcase extends advanced_testcase {
         login_attempt_failed($user);
         login_attempt_failed($user);
         $this->assertFalse(login_is_lockedout($user));
-        ob_start();
+        $sink = $this->redirectEmails();
         login_attempt_failed($user);
-        $output = ob_get_clean();
-        $this->assertContains('noemailever', $output);
+        $this->assertCount(1, $sink->get_messages());
+        $sink->close();
         $this->assertTrue(login_is_lockedout($user));
 
         // Test unlock works.
@@ -90,10 +89,10 @@ class core_authlib_testcase extends advanced_testcase {
 
         // Test lock duration works.
 
-        ob_start(); // Prevent nomailever notice.
+        $sink = $this->redirectEmails();
         login_attempt_failed($user);
-        $output = ob_get_clean();
-        $this->assertContains('noemailever', $output);
+        $this->assertCount(1, $sink->get_messages());
+        $sink->close();
         $this->assertTrue(login_is_lockedout($user));
         set_user_preference('login_lockout', time()-60*30+10, $user);
         $this->assertTrue(login_is_lockedout($user));
@@ -108,8 +107,6 @@ class core_authlib_testcase extends advanced_testcase {
         login_attempt_failed($user);
         login_attempt_failed($user);
         $this->assertFalse(login_is_lockedout($user));
-
-        ini_set('error_log', $oldlog);
     }
 
     public function test_authenticate_user_login() {
@@ -117,8 +114,7 @@ class core_authlib_testcase extends advanced_testcase {
 
         $this->resetAfterTest();
 
-        $oldlog = ini_get('error_log');
-        ini_set('error_log', "$CFG->dataroot/testlog.log"); // Prevent standard logging.
+        unset_config('noemailever');
 
         set_config('lockoutthreshold', 0);
         set_config('lockoutwindow', 60*20);
@@ -168,9 +164,10 @@ class core_authlib_testcase extends advanced_testcase {
         $result = authenticate_user_login('username1', 'nopass', false, $reason);
         $this->assertFalse($result);
         $this->assertEquals(AUTH_LOGIN_FAILED, $reason);
-        ob_start(); // Prevent nomailever notice.
+        $sink = $this->redirectEmails();
         $result = authenticate_user_login('username1', 'nopass', false, $reason);
-        ob_end_clean();
+        $this->assertCount(1, $sink->get_messages());
+        $sink->close();
         $this->assertFalse($result);
         $this->assertEquals(AUTH_LOGIN_FAILED, $reason);
 
@@ -181,8 +178,6 @@ class core_authlib_testcase extends advanced_testcase {
         $result = authenticate_user_login('username1', 'password1', true, $reason);
         $this->assertInstanceOf('stdClass', $result);
         $this->assertEquals(AUTH_LOGIN_OK, $reason);
-
-        ini_set('error_log', $oldlog);
     }
 
     public function test_user_loggedin_event_exceptions() {
diff --git a/lib/tests/messagelib_test.php b/lib/tests/messagelib_test.php
index c8a60238370..4f95515dd44 100644
--- a/lib/tests/messagelib_test.php
+++ b/lib/tests/messagelib_test.php
@@ -148,7 +148,7 @@ class core_messagelib_testcase extends advanced_testcase {
 
         // Set config setting to allow attachments.
         $CFG->allowattachments = true;
-        $CFG->noemailever = false;
+        unset_config('noemailever');
 
         $user = $this->getDataGenerator()->create_user();
         $context = context_user::instance($user->id);
diff --git a/lib/tests/moodlelib_test.php b/lib/tests/moodlelib_test.php
index ea638bcf0f4..1a81bc9efb7 100644
--- a/lib/tests/moodlelib_test.php
+++ b/lib/tests/moodlelib_test.php
@@ -2493,6 +2493,8 @@ class core_moodlelib_testcase extends advanced_testcase {
     }
 
     public function test_email_to_user() {
+        global $CFG;
+
         $this->resetAfterTest();
 
         $user1 = $this->getDataGenerator()->create_user();
@@ -2503,8 +2505,15 @@ class core_moodlelib_testcase extends advanced_testcase {
         $subject2 = 'subject 2';
         $messagetext2 = 'message text 2';
 
+        $this->assertNotEmpty($CFG->noemailever);
+        email_to_user($user1, $user2, $subject, $messagetext);
+        $this->assertDebuggingCalled('Not sending email due to $CFG->noemailever config setting');
+
         unset_config('noemailever');
 
+        email_to_user($user1, $user2, $subject, $messagetext);
+        $this->assertDebuggingCalled('Unit tests must not send real emails! Use $this->redirectEmails()');
+
         $sink = $this->redirectEmails();
         email_to_user($user1, $user2, $subject, $messagetext);
         email_to_user($user2, $user1, $subject2, $messagetext2);
@@ -2522,5 +2531,8 @@ class core_moodlelib_testcase extends advanced_testcase {
         $this->assertSame($messagetext2, trim($result[1]->body));
         $this->assertSame($user2->email, $result[1]->to);
         $this->assertSame($user1->email, $result[1]->from);
+
+        email_to_user($user1, $user2, $subject, $messagetext);
+        $this->assertDebuggingCalled('Unit tests must not send real emails! Use $this->redirectEmails()');
     }
 }
diff --git a/message/output/email/message_output_email.php b/message/output/email/message_output_email.php
index dd59c422902..cfe9fd460cf 100644
--- a/message/output/email/message_output_email.php
+++ b/message/output/email/message_output_email.php
@@ -39,11 +39,8 @@ class message_output_email extends message_output {
     function send_message($eventdata) {
         global $CFG;
 
-        if (!empty($CFG->noemailever)) {
-            // hidden setting for development sites, set in config.php if needed
-            debugging('$CFG->noemailever active, no email message sent.', DEBUG_MINIMAL);
-            return true;
-        }
+        // Ignore $CFG->noemailever here because we want to test this code,
+        // the message sending fails later in email_to_user().
 
         // skip any messaging suspended and deleted users
         if ($eventdata->userto->auth === 'nologin' or $eventdata->userto->suspended or $eventdata->userto->deleted) {
diff --git a/message/output/jabber/message_output_jabber.php b/message/output/jabber/message_output_jabber.php
index 199e2aad849..7556cd73da7 100644
--- a/message/output/jabber/message_output_jabber.php
+++ b/message/output/jabber/message_output_jabber.php
@@ -43,14 +43,19 @@ class message_output_jabber extends message_output {
     function send_message($eventdata){
         global $CFG;
 
-        if (!empty($CFG->noemailever)) {
-            // hidden setting for development sites, set in config.php if needed
-            debugging('$CFG->noemailever active, no jabber message sent.', DEBUG_MINIMAL);
+        // Skip any messaging of suspended and deleted users.
+        if ($eventdata->userto->auth === 'nologin' or $eventdata->userto->suspended or $eventdata->userto->deleted) {
             return true;
         }
 
-        // skip any messaging suspended and deleted users
-        if ($eventdata->userto->auth === 'nologin' or $eventdata->userto->suspended or $eventdata->userto->deleted) {
+        if (!empty($CFG->noemailever)) {
+            // hidden setting for development sites, set in config.php if needed
+            debugging('$CFG->noemailever is active, no jabber message sent.', DEBUG_MINIMAL);
+            return true;
+        }
+
+        if (PHPUNIT_TEST) {
+            // No connection to external servers allowed in phpunit tests.
             return true;
         }