diff --git a/admin/tool/task/cli/schedule_task.php b/admin/tool/task/cli/schedule_task.php
index 0660eff0556..62b0ad984cc 100644
--- a/admin/tool/task/cli/schedule_task.php
+++ b/admin/tool/task/cli/schedule_task.php
@@ -123,6 +123,7 @@ if ($execute = $options['execute']) {
         } else {
             $task->set_cron_lock($cronlock);
         }
+        get_mailer('buffer');
         $task->execute();
         if (isset($predbqueries)) {
             mtrace("... used " . ($DB->perf_get_queries() - $predbqueries) . " dbqueries");
@@ -130,6 +131,7 @@ if ($execute = $options['execute']) {
         }
         mtrace("Task completed.");
         \core\task\manager::scheduled_task_complete($task);
+        get_mailer('close');
         exit(0);
     } catch (Exception $e) {
         if ($DB->is_transaction_started()) {
@@ -139,6 +141,7 @@ if ($execute = $options['execute']) {
         mtrace("... used " . (microtime(true) - $pretime) . " seconds");
         mtrace("Task failed: " . $e->getMessage());
         \core\task\manager::scheduled_task_failed($task);
+        get_mailer('close');
         exit(1);
     }
 }
diff --git a/lib/classes/task/legacy_plugin_cron_task.php b/lib/classes/task/legacy_plugin_cron_task.php
index b2d08733715..4aa1f451877 100644
--- a/lib/classes/task/legacy_plugin_cron_task.php
+++ b/lib/classes/task/legacy_plugin_cron_task.php
@@ -79,7 +79,6 @@ class legacy_plugin_cron_task extends scheduled_task {
 
         // Run all cron jobs for each module.
         mtrace("Starting activity modules");
-        get_mailer('buffer');
         if ($mods = $DB->get_records_select("modules", "cron > 0 AND ((? - lastcron) > cron) AND visible = 1", array($timenow))) {
             foreach ($mods as $mod) {
                 $libfile = "$CFG->dirroot/mod/$mod->name/lib.php";
@@ -105,7 +104,6 @@ class legacy_plugin_cron_task extends scheduled_task {
                 }
             }
         }
-        get_mailer('close');
         mtrace("Finished activity modules");
 
         mtrace("Starting blocks");
diff --git a/lib/cronlib.php b/lib/cronlib.php
index 4312ba6900c..cb8bb988272 100644
--- a/lib/cronlib.php
+++ b/lib/cronlib.php
@@ -70,6 +70,7 @@ function cron_run() {
         $predbqueries = $DB->perf_get_queries();
         $pretime      = microtime(1);
         try {
+            get_mailer('buffer');
             $task->execute();
             if (isset($predbqueries)) {
                 mtrace("... used " . ($DB->perf_get_queries() - $predbqueries) . " dbqueries");
@@ -89,6 +90,7 @@ function cron_run() {
             mtrace("Scheduled task failed: " . $task->get_name() . "," . $e->getMessage());
             \core\task\manager::scheduled_task_failed($task);
         }
+        get_mailer('close');
         unset($task);
     }
 
@@ -101,6 +103,7 @@ function cron_run() {
         $predbqueries = $DB->perf_get_queries();
         $pretime      = microtime(1);
         try {
+            get_mailer('buffer');
             $task->execute();
             if (isset($predbqueries)) {
                 mtrace("... used " . ($DB->perf_get_queries() - $predbqueries) . " dbqueries");
@@ -120,6 +123,7 @@ function cron_run() {
             mtrace("Adhoc task failed: " . get_class($task) . "," . $e->getMessage());
             \core\task\manager::adhoc_task_failed($task);
         }
+        get_mailer('close');
         unset($task);
     }