MAGETWO-71696: Merge 2.2-develop into develop

Author: slavvka

app/code/Magento/Email/Test/Unit/Model/TransportTest.php

@@ -0,0 +1,23 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace Magento\Framework\Mail\Test\Unit;
+
+class TransportTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @covers \Magento\Framework\Mail\Transport::sendMessage
+     * @expectedException \Magento\Framework\Exception\MailException
+     * @expectedExceptionMessage Invalid email; contains no "To" header
+     */
+    public function testSendMessageBrokenMessage()
+    {
+        $transport = new \Magento\Framework\Mail\Transport(
+            new \Magento\Framework\Mail\Message()
+        );
+
+        $transport->sendMessage();
+    }
+}