Change Encoding of MIME Emails to QUOTED-PRINTABLE

Added Content-Disposition: inline to all MIME emails

Implementation now matches previous ZF1 implementation

dev/tests/integration/testsuite/Magento/Customer/Controller/AccountTest.php

@@ -771,7 +771,7 @@ public function testConfirmationEmailWithSpecialCharacters(): void
 
         $this->assertContains('To: ' . $email, $rawMessage);
 
-        $content = $message->getBody()->getPartContent(0);
+        $content = $message->getBody()->getParts()[0]->getRawContent();
         $confirmationUrl = $this->getConfirmationUrlFromMessageContent($content);
         $this->setRequestInfo($confirmationUrl, 'confirm');
         $this->clearCookieMessagesList();

dev/tests/integration/testsuite/Magento/Newsletter/Model/SubscriberTest.php

@@ -7,6 +7,9 @@
 
 use Magento\TestFramework\Mail\Template\TransportBuilderMock;
 
+/**
+ * \Magento\Newsletter\Model\Subscriber tests
+ */
 class SubscriberTest extends \PHPUnit\Framework\TestCase
 {
     /**
@@ -35,7 +38,7 @@ public function testEmailConfirmation()
         $this->assertContains(
             '/newsletter/subscriber/confirm/id/' . $this->model->getSubscriberId()
             . '/code/ysayquyajua23iq29gxwu2eax2qb6gvy',
-            $transportBuilder->getSentMessage()->getRawMessage()
+            $transportBuilder->getSentMessage()->getBody()->getParts()[0]->getRawContent()
         );
         $this->assertEquals(Subscriber::STATUS_NOT_ACTIVE, $this->model->getSubscriberStatus());
     }

dev/tests/integration/testsuite/Magento/Sales/Controller/Adminhtml/Order/Create/SaveTest.php

@@ -142,7 +142,7 @@ public function testSendEmailOnOrderSave(): void
         );
 
         $this->assertEquals($message->getSubject(), $subject);
-        $this->assertThat($message->getRawMessage(), $assert);
+        $this->assertThat($message->getBody()->getParts()[0]->getRawContent(), $assert);
     }
 
     /**

dev/tests/integration/testsuite/Magento/Sales/Controller/Adminhtml/Order/Creditmemo/AddCommentTest.php

@@ -54,7 +54,7 @@ public function testSendEmailOnAddCreditmemoComment(): void
         );
 
         $this->assertEquals($message->getSubject(), $subject);
-        $this->assertThat($message->getRawMessage(), $messageConstraint);
+        $this->assertThat($message->getBody()->getParts()[0]->getRawContent(), $messageConstraint);
     }
 
     /**

dev/tests/integration/testsuite/Magento/Sales/Controller/Adminhtml/Order/Creditmemo/SaveTest.php

@@ -56,7 +56,7 @@ public function testSendEmailOnCreditmemoSave(): void
         );
 
         $this->assertEquals($message->getSubject(), $subject);
-        $this->assertThat($message->getRawMessage(), $messageConstraint);
+        $this->assertThat($message->getBody()->getParts()[0]->getRawContent(), $messageConstraint);
     }
 
     /**

dev/tests/integration/testsuite/Magento/Sales/Controller/Adminhtml/Order/EmailTest.php

@@ -82,7 +82,7 @@ public function testSendOrderEmail(): void
         );
 
         $this->assertEquals($message->getSubject(), $subject);
-        $this->assertThat($message->getRawMessage(), $assert);
+        $this->assertThat($message->getBody()->getParts()[0]->getRawContent(), $assert);
     }
 
     /**

dev/tests/integration/testsuite/Magento/Sales/Controller/Adminhtml/Order/Invoice/AddCommentTest.php

@@ -55,7 +55,7 @@ public function testSendEmailOnAddInvoiceComment(): void
         );
 
         $this->assertEquals($message->getSubject(), $subject);
-        $this->assertThat($message->getRawMessage(), $messageConstraint);
+        $this->assertThat($message->getBody()->getParts()[0]->getRawContent(), $messageConstraint);
     }
 
     /**

dev/tests/integration/testsuite/Magento/Sales/Controller/Adminhtml/Order/Invoice/EmailTest.php

@@ -59,7 +59,7 @@ public function testSendInvoiceEmail(): void
         );
 
         $this->assertEquals($message->getSubject(), $subject);
-        $this->assertThat($message->getRawMessage(), $messageConstraint);
+        $this->assertThat($message->getBody()->getParts()[0]->getRawContent(), $messageConstraint);
     }
 
     /**

dev/tests/integration/testsuite/Magento/Sales/Controller/Adminhtml/Order/Invoice/SaveTest.php

@@ -51,7 +51,7 @@ public function testSendEmailOnInvoiceSave(): void
         );
 
         $this->assertEquals($message->getSubject(), $subject);
-        $this->assertThat($message->getRawMessage(), $messageConstraint);
+        $this->assertThat($message->getBody()->getParts()[0]->getRawContent(), $messageConstraint);
     }
 
     /**

dev/tests/integration/testsuite/Magento/Sales/Model/Order/CreateTest.php

@@ -95,6 +95,6 @@ public function testSendEmailOnOrderPlace(): void
         );
 
         $this->assertEquals($message->getSubject(), $subject);
-        $this->assertThat($message->getRawMessage(), $assert);
+        $this->assertThat($message->getBody()->getParts()[0]->getRawContent(), $assert);
     }
 }

dev/tests/integration/testsuite/Magento/Shipping/Controller/Adminhtml/Order/Shipment/AddCommentTest.php

@@ -54,7 +54,7 @@ public function testSendEmailOnShipmentCommentAdd(): void
         );
 
         $this->assertEquals($message->getSubject(), $subject);
-        $this->assertThat($message->getRawMessage(), $messageConstraint);
+        $this->assertThat($message->getBody()->getParts()[0]->getRawContent(), $messageConstraint);
     }
 
     /**

dev/tests/integration/testsuite/Magento/Shipping/Controller/Adminhtml/Order/Shipment/SaveTest.php

@@ -51,7 +51,7 @@ public function testSendEmailOnShipmentSave(): void
         );
 
         $this->assertEquals($message->getSubject(), $subject);
-        $this->assertThat($message->getRawMessage(), $messageConstraint);
+        $this->assertThat($message->getBody()->getParts()[0]->getRawContent(), $messageConstraint);
     }
 
     /**

lib/internal/Magento/Framework/Mail/Message.php

@@ -167,6 +167,8 @@ private function createMimeFromString($body, $messageType)
     {
         $part = new Part($body);
         $part->setCharset($this->zendMessage->getEncoding());
+        $part->setEncoding(Mime::ENCODING_QUOTEDPRINTABLE);
+        $part->setDisposition(Mime::DISPOSITION_INLINE);
         $part->setType($messageType);
         $mimeMessage = new \Zend\Mime\Message();
         $mimeMessage->addPart($part);

lib/internal/Magento/Framework/Mail/Test/Unit/MessageTest.php

@@ -26,9 +26,10 @@ public function testSetBodyHtml()
 
         $part = $this->message->getBody()->getParts()[0];
         $this->assertEquals('text/html', $part->getType());
-        $this->assertEquals('8bit', $part->getEncoding());
+        $this->assertEquals('quoted-printable', $part->getEncoding());
         $this->assertEquals('utf-8', $part->getCharset());
         $this->assertEquals('body', $part->getContent());
+        $this->assertEquals('inline', $part->getDisposition());
     }
 
     public function testSetBodyText()
@@ -37,8 +38,9 @@ public function testSetBodyText()
 
         $part = $this->message->getBody()->getParts()[0];
         $this->assertEquals('text/plain', $part->getType());
-        $this->assertEquals('8bit', $part->getEncoding());
+        $this->assertEquals('quoted-printable', $part->getEncoding());
         $this->assertEquals('utf-8', $part->getCharset());
         $this->assertEquals('body', $part->getContent());
+        $this->assertEquals('inline', $part->getDisposition());
     }
 }