diff --git a/phpBB/includes/functions_messenger.php b/phpBB/includes/functions_messenger.php
index 390463fe3a..dd22f6bb9c 100644
--- a/phpBB/includes/functions_messenger.php
+++ b/phpBB/includes/functions_messenger.php
@@ -581,7 +581,7 @@ class messenger
 	 */
 	function get_transport($dummy = false)
 	{
-		if ($dummy)
+		if ($dummy || empty($this->config['smtp_host']))
 		{
 			$dsn = 'null://null';
 		}
@@ -600,7 +600,7 @@ class messenger
 
 		$transport = Transport::fromDsn($dsn);
 
-		if ($this->config['smtp_delivery'])
+		if ($this->config['smtp_delivery'] && $dsn != 'null://null')
 		{
 			// Set ssl context options, see http://php.net/manual/en/context.ssl.php
 			$verify_peer = (bool) $this->config['smtp_verify_peer'];
diff --git a/tests/test_framework/phpbb_functional_test_case.php b/tests/test_framework/phpbb_functional_test_case.php
index 2ce670d390..ddfca1e0be 100644
--- a/tests/test_framework/phpbb_functional_test_case.php
+++ b/tests/test_framework/phpbb_functional_test_case.php
@@ -418,7 +418,7 @@ class phpbb_functional_test_case extends phpbb_test_case
 
 		$iohandler->set_input('email_enable', true);
 		$iohandler->set_input('smtp_delivery', '1');
-		$iohandler->set_input('smtp_host', 'nxdomain.phpbb.com');
+		$iohandler->set_input('smtp_host', '');
 		$iohandler->set_input('smtp_auth', 'PLAIN');
 		$iohandler->set_input('smtp_user', 'nxuser');
 		$iohandler->set_input('smtp_pass', 'nxpass');