diff --git a/src/DSNConfigurator.php b/src/DSNConfigurator.php
index fdc13c86..39a4ff29 100644
--- a/src/DSNConfigurator.php
+++ b/src/DSNConfigurator.php
@@ -123,7 +123,7 @@ class DSNConfigurator
         $isSMTPS = 'smtps' === $config['scheme'];
 
         if ($isSMTPS) {
-            $mailer->SMTPSecure = 'tls';
+            $mailer->SMTPSecure = PHPMailer::ENCRYPTION_STARTTLS;
         }
 
         $mailer->Host = $config['host'];
diff --git a/test/PHPMailer/DSNConfiguratorTest.php b/test/PHPMailer/DSNConfiguratorTest.php
index 3cd3bd4a..7ae61ea0 100644
--- a/test/PHPMailer/DSNConfiguratorTest.php
+++ b/test/PHPMailer/DSNConfiguratorTest.php
@@ -15,6 +15,7 @@ namespace PHPMailer\Test\PHPMailer;
 
 use PHPMailer\PHPMailer\DSNConfigurator;
 use PHPMailer\PHPMailer\Exception;
+use PHPMailer\PHPMailer\PHPMailer;
 use PHPMailer\PHPMailer\SMTP;
 use PHPMailer\Test\TestCase;
 
@@ -40,6 +41,15 @@ final class DSNConfiguratorTest extends TestCase
         $configurator->configure($this->Mail, 'ftp://localhost');
     }
 
+    public function testConfigureMail()
+    {
+        $configurator = new DSNConfigurator();
+
+        $configurator->configure($this->Mail, 'mail://localhost');
+
+        $this->assertEquals($this->Mail->Mailer, 'mail');
+    }
+
     public function testConfigureSendmail()
     {
         $configurator = new DSNConfigurator();
@@ -49,6 +59,15 @@ final class DSNConfiguratorTest extends TestCase
         $this->assertEquals($this->Mail->Mailer, 'sendmail');
     }
 
+    public function testConfigureQmail()
+    {
+        $configurator = new DSNConfigurator();
+
+        $configurator->configure($this->Mail, 'qmail://localhost');
+
+        $this->assertEquals($this->Mail->Mailer, 'qmail');
+    }
+
     public function testConfigureSmtpWithoutAuthentication()
     {
         $configurator = new DSNConfigurator();
@@ -67,12 +86,35 @@ final class DSNConfiguratorTest extends TestCase
         $configurator->configure($this->Mail, 'smtp://user:pass@remotehost');
 
         $this->assertEquals($this->Mail->Mailer, 'smtp');
-        $this->assertTrue($this->Mail->SMTPAuth);
         $this->assertEquals($this->Mail->Host, 'remotehost');
+
+        $this->assertTrue($this->Mail->SMTPAuth);
         $this->assertEquals($this->Mail->Username, 'user');
         $this->assertEquals($this->Mail->Password, 'pass');
     }
 
+    public function testConfigureSmtpWithoutPort()
+    {
+        $configurator = new DSNConfigurator();
+
+        $configurator->configure($this->Mail, 'smtp://localhost');
+
+        $this->assertEquals($this->Mail->Mailer, 'smtp');
+        $this->assertEquals($this->Mail->Host, 'localhost');
+        $this->assertEquals($this->Mail->Port, SMTP::DEFAULT_PORT);
+    }
+
+    public function testConfigureSmtpWitPort()
+    {
+        $configurator = new DSNConfigurator();
+
+        $configurator->configure($this->Mail, 'smtp://localhost:2525');
+
+        $this->assertEquals($this->Mail->Mailer, 'smtp');
+        $this->assertEquals($this->Mail->Host, 'localhost');
+        $this->assertEquals($this->Mail->Port, 2525);
+    }
+
     public function testConfigureSmtpsWithoutPort()
     {
         $configurator = new DSNConfigurator();
@@ -80,11 +122,13 @@ final class DSNConfiguratorTest extends TestCase
         $configurator->configure($this->Mail, 'smtps://user:pass@remotehost');
 
         $this->assertEquals($this->Mail->Mailer, 'smtp');
-        $this->assertEquals($this->Mail->SMTPSecure, 'tls');
-        $this->assertTrue($this->Mail->SMTPAuth);
+        $this->assertEquals($this->Mail->SMTPSecure, PHPMailer::ENCRYPTION_STARTTLS);
+
         $this->assertEquals($this->Mail->Host, 'remotehost');
+        $this->assertEquals($this->Mail->Port, SMTP::DEFAULT_SECURE_PORT);
+
+        $this->assertTrue($this->Mail->SMTPAuth);
         $this->assertEquals($this->Mail->Username, 'user');
         $this->assertEquals($this->Mail->Password, 'pass');
-        $this->assertEquals($this->Mail->Port, SMTP::DEFAULT_SECURE_PORT);
     }
 }