diff --git a/app/code/Magento/Sales/Model/Order/Creditmemo/Sender/EmailSender.php b/app/code/Magento/Sales/Model/Order/Creditmemo/Sender/EmailSender.php
index c51000695fe20..0636f7cf96995 100644
--- a/app/code/Magento/Sales/Model/Order/Creditmemo/Sender/EmailSender.php
+++ b/app/code/Magento/Sales/Model/Order/Creditmemo/Sender/EmailSender.php
@@ -7,9 +7,12 @@
 
 use Magento\Sales\Model\Order\Email\Sender;
 use Magento\Sales\Model\Order\Creditmemo\SenderInterface;
+use Magento\Framework\DataObject;
 
 /**
  * Email notification sender for Creditmemo.
+ *
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
  */
 class EmailSender extends Sender implements SenderInterface
 {
@@ -106,13 +109,17 @@ public function send(
                 'formattedShippingAddress' => $this->getFormattedShippingAddress($order),
                 'formattedBillingAddress' => $this->getFormattedBillingAddress($order),
             ];
+            $transportObject = new DataObject($transport);
 
+            /**
+             * Event argument `transport` is @deprecated. Use `transportObject` instead.
+             */
             $this->eventManager->dispatch(
                 'email_creditmemo_set_template_vars_before',
-                ['sender' => $this, 'transport' => $transport]
+                ['sender' => $this, 'transport' => $transportObject->getData(), 'transportObject' => $transportObject]
             );
 
-            $this->templateContainer->setTemplateVars($transport);
+            $this->templateContainer->setTemplateVars($transportObject->getData());
 
             if ($this->checkAndSend($order)) {
                 $creditmemo->setEmailSent(true);
diff --git a/app/code/Magento/Sales/Model/Order/Email/Sender/CreditmemoCommentSender.php b/app/code/Magento/Sales/Model/Order/Email/Sender/CreditmemoCommentSender.php
index 35f702c540238..e71b47a7e75b3 100644
--- a/app/code/Magento/Sales/Model/Order/Email/Sender/CreditmemoCommentSender.php
+++ b/app/code/Magento/Sales/Model/Order/Email/Sender/CreditmemoCommentSender.php
@@ -12,6 +12,7 @@
 use Magento\Sales\Model\Order\Email\NotifySender;
 use Magento\Sales\Model\Order\Address\Renderer;
 use Magento\Framework\Event\ManagerInterface;
+use Magento\Framework\DataObject;
 
 /**
  * Class CreditmemoCommentSender
@@ -71,13 +72,17 @@ public function send(Creditmemo $creditmemo, $notify = true, $comment = '')
             'formattedShippingAddress' => $this->getFormattedShippingAddress($order),
             'formattedBillingAddress' => $this->getFormattedBillingAddress($order),
         ];
+        $transportObject = new DataObject($transport);
 
+        /**
+         * Event argument `transport` is @deprecated. Use `transportObject` instead.
+         */
         $this->eventManager->dispatch(
             'email_creditmemo_comment_set_template_vars_before',
-            ['sender' => $this, 'transport' => $transport]
+            ['sender' => $this, 'transport' => $transportObject->getData(), 'transportObject' => $transportObject]
         );
 
-        $this->templateContainer->setTemplateVars($transport);
+        $this->templateContainer->setTemplateVars($transportObject->getData());
 
         return $this->checkAndSend($order, $notify);
     }
diff --git a/app/code/Magento/Sales/Model/Order/Email/Sender/CreditmemoSender.php b/app/code/Magento/Sales/Model/Order/Email/Sender/CreditmemoSender.php
index 5e88b119e68b3..2c2eea9da8b5c 100644
--- a/app/code/Magento/Sales/Model/Order/Email/Sender/CreditmemoSender.php
+++ b/app/code/Magento/Sales/Model/Order/Email/Sender/CreditmemoSender.php
@@ -14,6 +14,7 @@
 use Magento\Sales\Model\ResourceModel\Order\Creditmemo as CreditmemoResource;
 use Magento\Sales\Model\Order\Address\Renderer;
 use Magento\Framework\Event\ManagerInterface;
+use Magento\Framework\DataObject;
 
 /**
  * Class CreditmemoSender
@@ -102,7 +103,7 @@ public function send(Creditmemo $creditmemo, $forceSyncMode = false)
 
         if (!$this->globalConfig->getValue('sales_email/general/async_sending') || $forceSyncMode) {
             $order = $creditmemo->getOrder();
-            
+
             $transport = [
                 'order' => $order,
                 'creditmemo' => $creditmemo,
@@ -113,13 +114,17 @@ public function send(Creditmemo $creditmemo, $forceSyncMode = false)
                 'formattedShippingAddress' => $this->getFormattedShippingAddress($order),
                 'formattedBillingAddress' => $this->getFormattedBillingAddress($order),
             ];
+            $transportObject = new DataObject($transport);
 
+            /**
+             * Event argument `transport` is @deprecated. Use `transportObject` instead.
+             */
             $this->eventManager->dispatch(
                 'email_creditmemo_set_template_vars_before',
-                ['sender' => $this, 'transport' => $transport]
+                ['sender' => $this, 'transport' => $transportObject->getData(), 'transportObject' => $transportObject]
             );
 
-            $this->templateContainer->setTemplateVars($transport);
+            $this->templateContainer->setTemplateVars($transportObject->getData());
 
             if ($this->checkAndSend($order)) {
                 $creditmemo->setEmailSent(true);
diff --git a/app/code/Magento/Sales/Model/Order/Email/Sender/InvoiceCommentSender.php b/app/code/Magento/Sales/Model/Order/Email/Sender/InvoiceCommentSender.php
index 03a6ad522acac..b0ec4846332a6 100644
--- a/app/code/Magento/Sales/Model/Order/Email/Sender/InvoiceCommentSender.php
+++ b/app/code/Magento/Sales/Model/Order/Email/Sender/InvoiceCommentSender.php
@@ -12,6 +12,7 @@
 use Magento\Sales\Model\Order\Invoice;
 use Magento\Sales\Model\Order\Address\Renderer;
 use Magento\Framework\Event\ManagerInterface;
+use Magento\Framework\DataObject;
 
 /**
  * Class InvoiceCommentSender
@@ -71,13 +72,17 @@ public function send(Invoice $invoice, $notify = true, $comment = '')
             'formattedShippingAddress' => $this->getFormattedShippingAddress($order),
             'formattedBillingAddress' => $this->getFormattedBillingAddress($order),
         ];
+        $transportObject = new DataObject($transport);
 
+        /**
+         * Event argument `transport` is @deprecated. Use `transportObject` instead.
+         */
         $this->eventManager->dispatch(
             'email_invoice_comment_set_template_vars_before',
-            ['sender' => $this, 'transport' => $transport]
+            ['sender' => $this, 'transport' => $transportObject->getData(), 'transportObject' => $transportObject]
         );
 
-        $this->templateContainer->setTemplateVars($transport);
+        $this->templateContainer->setTemplateVars($transportObject->getData());
 
         return $this->checkAndSend($order, $notify);
     }
diff --git a/app/code/Magento/Sales/Model/Order/Email/Sender/InvoiceSender.php b/app/code/Magento/Sales/Model/Order/Email/Sender/InvoiceSender.php
index 13b783824d096..d51d01db33614 100644
--- a/app/code/Magento/Sales/Model/Order/Email/Sender/InvoiceSender.php
+++ b/app/code/Magento/Sales/Model/Order/Email/Sender/InvoiceSender.php
@@ -14,6 +14,7 @@
 use Magento\Sales\Model\ResourceModel\Order\Invoice as InvoiceResource;
 use Magento\Sales\Model\Order\Address\Renderer;
 use Magento\Framework\Event\ManagerInterface;
+use Magento\Framework\DataObject;
 
 /**
  * Class InvoiceSender
@@ -113,13 +114,17 @@ public function send(Invoice $invoice, $forceSyncMode = false)
                 'formattedShippingAddress' => $this->getFormattedShippingAddress($order),
                 'formattedBillingAddress' => $this->getFormattedBillingAddress($order)
             ];
+            $transportObject = new DataObject($transport);
 
+            /**
+             * Event argument `transport` is @deprecated. Use `transportObject` instead.
+             */
             $this->eventManager->dispatch(
                 'email_invoice_set_template_vars_before',
-                ['sender' => $this, 'transport' => $transport]
+                ['sender' => $this, 'transport' => $transportObject->getData(), 'transportObject' => $transportObject]
             );
 
-            $this->templateContainer->setTemplateVars($transport);
+            $this->templateContainer->setTemplateVars($transportObject->getData());
 
             if ($this->checkAndSend($order)) {
                 $invoice->setEmailSent(true);
diff --git a/app/code/Magento/Sales/Model/Order/Email/Sender/OrderCommentSender.php b/app/code/Magento/Sales/Model/Order/Email/Sender/OrderCommentSender.php
index bbccb34c8963a..4d900f467948c 100644
--- a/app/code/Magento/Sales/Model/Order/Email/Sender/OrderCommentSender.php
+++ b/app/code/Magento/Sales/Model/Order/Email/Sender/OrderCommentSender.php
@@ -11,6 +11,7 @@
 use Magento\Sales\Model\Order\Email\NotifySender;
 use Magento\Sales\Model\Order\Address\Renderer;
 use Magento\Framework\Event\ManagerInterface;
+use Magento\Framework\DataObject;
 
 /**
  * Class OrderCommentSender
@@ -68,13 +69,17 @@ public function send(Order $order, $notify = true, $comment = '')
             'formattedShippingAddress' => $this->getFormattedShippingAddress($order),
             'formattedBillingAddress' => $this->getFormattedBillingAddress($order),
         ];
+        $transportObject = new DataObject($transport);
 
+        /**
+         * Event argument `transport` is @deprecated. Use `transportObject` instead.
+         */
         $this->eventManager->dispatch(
             'email_order_comment_set_template_vars_before',
-            ['sender' => $this, 'transport' => $transport]
+            ['sender' => $this, 'transport' => $transportObject->getData(), 'transportObject' => $transportObject]
         );
 
-        $this->templateContainer->setTemplateVars($transport);
+        $this->templateContainer->setTemplateVars($transportObject->getData());
 
         return $this->checkAndSend($order, $notify);
     }
diff --git a/app/code/Magento/Sales/Model/Order/Email/Sender/ShipmentCommentSender.php b/app/code/Magento/Sales/Model/Order/Email/Sender/ShipmentCommentSender.php
index bbe7d6130a414..bdbef9b8b1b11 100644
--- a/app/code/Magento/Sales/Model/Order/Email/Sender/ShipmentCommentSender.php
+++ b/app/code/Magento/Sales/Model/Order/Email/Sender/ShipmentCommentSender.php
@@ -12,6 +12,7 @@
 use Magento\Sales\Model\Order\Shipment;
 use Magento\Sales\Model\Order\Address\Renderer;
 use Magento\Framework\Event\ManagerInterface;
+use Magento\Framework\DataObject;
 
 /**
  * Class ShipmentCommentSender
@@ -71,13 +72,17 @@ public function send(Shipment $shipment, $notify = true, $comment = '')
             'formattedShippingAddress' => $this->getFormattedShippingAddress($order),
             'formattedBillingAddress' => $this->getFormattedBillingAddress($order),
         ];
+        $transportObject = new DataObject($transport);
 
+        /**
+         * Event argument `transport` is @deprecated. Use `transportObject` instead.
+         */
         $this->eventManager->dispatch(
             'email_shipment_comment_set_template_vars_before',
-            ['sender' => $this, 'transport' => $transport]
+            ['sender' => $this, 'transport' => $transportObject->getData(), 'transportObject' => $transportObject]
         );
 
-        $this->templateContainer->setTemplateVars($transport);
+        $this->templateContainer->setTemplateVars($transportObject->getData());
 
         return $this->checkAndSend($order, $notify);
     }
diff --git a/app/code/Magento/Sales/Model/Order/Email/Sender/ShipmentSender.php b/app/code/Magento/Sales/Model/Order/Email/Sender/ShipmentSender.php
index 87bb68088b7a8..5f29bcf333aa3 100644
--- a/app/code/Magento/Sales/Model/Order/Email/Sender/ShipmentSender.php
+++ b/app/code/Magento/Sales/Model/Order/Email/Sender/ShipmentSender.php
@@ -14,6 +14,7 @@
 use Magento\Sales\Model\ResourceModel\Order\Shipment as ShipmentResource;
 use Magento\Sales\Model\Order\Address\Renderer;
 use Magento\Framework\Event\ManagerInterface;
+use Magento\Framework\DataObject;
 
 /**
  * Class ShipmentSender
@@ -102,7 +103,7 @@ public function send(Shipment $shipment, $forceSyncMode = false)
 
         if (!$this->globalConfig->getValue('sales_email/general/async_sending') || $forceSyncMode) {
             $order = $shipment->getOrder();
-            
+
             $transport = [
                 'order' => $order,
                 'shipment' => $shipment,
@@ -113,13 +114,17 @@ public function send(Shipment $shipment, $forceSyncMode = false)
                 'formattedShippingAddress' => $this->getFormattedShippingAddress($order),
                 'formattedBillingAddress' => $this->getFormattedBillingAddress($order)
             ];
+            $transportObject = new DataObject($transport);
 
+            /**
+             * Event argument `transport` is @deprecated. Use `transportObject` instead.
+             */
             $this->eventManager->dispatch(
                 'email_shipment_set_template_vars_before',
-                ['sender' => $this, 'transport' => $transport]
+                ['sender' => $this, 'transport' => $transportObject->getData(), 'transportObject' => $transportObject]
             );
 
-            $this->templateContainer->setTemplateVars($transport);
+            $this->templateContainer->setTemplateVars($transportObject->getData());
 
             if ($this->checkAndSend($order)) {
                 $shipment->setEmailSent(true);
diff --git a/app/code/Magento/Sales/Model/Order/Invoice/Sender/EmailSender.php b/app/code/Magento/Sales/Model/Order/Invoice/Sender/EmailSender.php
index c15e5014bacbd..961de973bd6e0 100644
--- a/app/code/Magento/Sales/Model/Order/Invoice/Sender/EmailSender.php
+++ b/app/code/Magento/Sales/Model/Order/Invoice/Sender/EmailSender.php
@@ -7,9 +7,12 @@
 
 use Magento\Sales\Model\Order\Email\Sender;
 use Magento\Sales\Model\Order\Invoice\SenderInterface;
+use Magento\Framework\DataObject;
 
 /**
  * Email notification sender for Invoice.
+ *
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
  */
 class EmailSender extends Sender implements SenderInterface
 {
@@ -104,15 +107,19 @@ public function send(
                 'payment_html' => $this->getPaymentHtml($order),
                 'store' => $order->getStore(),
                 'formattedShippingAddress' => $this->getFormattedShippingAddress($order),
-                'formattedBillingAddress' => $this->getFormattedBillingAddress($order)
+                'formattedBillingAddress' => $this->getFormattedBillingAddress($order),
             ];
+            $transportObject = new DataObject($transport);
 
+            /**
+             * Event argument `transport` is @deprecated. Use `transportObject` instead.
+             */
             $this->eventManager->dispatch(
                 'email_invoice_set_template_vars_before',
-                ['sender' => $this, 'transport' => $transport]
+                ['sender' => $this, 'transport' => $transportObject->getData(), 'transportObject' => $transportObject]
             );
 
-            $this->templateContainer->setTemplateVars($transport);
+            $this->templateContainer->setTemplateVars($transportObject->getData());
 
             if ($this->checkAndSend($order)) {
                 $invoice->setEmailSent(true);
diff --git a/app/code/Magento/Sales/Model/Order/Shipment/Sender/EmailSender.php b/app/code/Magento/Sales/Model/Order/Shipment/Sender/EmailSender.php
index eb6766ab86d1a..f403e84f0248d 100644
--- a/app/code/Magento/Sales/Model/Order/Shipment/Sender/EmailSender.php
+++ b/app/code/Magento/Sales/Model/Order/Shipment/Sender/EmailSender.php
@@ -7,9 +7,12 @@
 
 use Magento\Sales\Model\Order\Email\Sender;
 use Magento\Sales\Model\Order\Shipment\SenderInterface;
+use Magento\Framework\DataObject;
 
 /**
  * Email notification sender for Shipment.
+ *
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
  */
 class EmailSender extends Sender implements SenderInterface
 {
@@ -106,13 +109,17 @@ public function send(
                 'formattedShippingAddress' => $this->getFormattedShippingAddress($order),
                 'formattedBillingAddress' => $this->getFormattedBillingAddress($order)
             ];
+            $transportObject = new DataObject($transport);
 
+            /**
+             * Event argument `transport` is @deprecated. Use `transportObject` instead.
+             */
             $this->eventManager->dispatch(
                 'email_shipment_set_template_vars_before',
-                ['sender' => $this, 'transport' => $transport]
+                ['sender' => $this, 'transport' => $transportObject->getData(), 'transportObject' => $transportObject]
             );
 
-            $this->templateContainer->setTemplateVars($transport);
+            $this->templateContainer->setTemplateVars($transportObject->getData());
 
             if ($this->checkAndSend($order)) {
                 $shipment->setEmailSent(true);
diff --git a/app/code/Magento/Sales/Test/Unit/Model/Order/Creditmemo/Sender/EmailSenderTest.php b/app/code/Magento/Sales/Test/Unit/Model/Order/Creditmemo/Sender/EmailSenderTest.php
index 294d44d5039de..1c91cc87675c0 100644
--- a/app/code/Magento/Sales/Test/Unit/Model/Order/Creditmemo/Sender/EmailSenderTest.php
+++ b/app/code/Magento/Sales/Test/Unit/Model/Order/Creditmemo/Sender/EmailSenderTest.php
@@ -262,6 +262,7 @@ public function testSend($configValue, $forceSyncMode, $isComment, $emailSending
                 'formattedShippingAddress' => 'Formatted address',
                 'formattedBillingAddress' => 'Formatted address',
             ];
+            $transport = new \Magento\Framework\DataObject($transport);
 
             $this->eventManagerMock->expects($this->once())
                 ->method('dispatch')
@@ -269,13 +270,14 @@ public function testSend($configValue, $forceSyncMode, $isComment, $emailSending
                     'email_creditmemo_set_template_vars_before',
                     [
                         'sender' => $this->subject,
-                        'transport' => $transport,
+                        'transport' => $transport->getData(),
+                        'transportObject' => $transport
                     ]
                 );
 
             $this->templateContainerMock->expects($this->once())
                 ->method('setTemplateVars')
-                ->with($transport);
+                ->with($transport->getData());
 
             $this->identityContainerMock->expects($this->once())
                 ->method('isEnabled')
diff --git a/app/code/Magento/Sales/Test/Unit/Model/Order/Invoice/Sender/EmailSenderTest.php b/app/code/Magento/Sales/Test/Unit/Model/Order/Invoice/Sender/EmailSenderTest.php
index 0fb61be74def3..689285a4524d1 100644
--- a/app/code/Magento/Sales/Test/Unit/Model/Order/Invoice/Sender/EmailSenderTest.php
+++ b/app/code/Magento/Sales/Test/Unit/Model/Order/Invoice/Sender/EmailSenderTest.php
@@ -258,8 +258,9 @@ public function testSend($configValue, $forceSyncMode, $isComment, $emailSending
                 'payment_html' => 'Payment Info Block',
                 'store' => $this->storeMock,
                 'formattedShippingAddress' => 'Formatted address',
-                'formattedBillingAddress' => 'Formatted address'
+                'formattedBillingAddress' => 'Formatted address',
             ];
+            $transport = new \Magento\Framework\DataObject($transport);
 
             $this->eventManagerMock->expects($this->once())
                 ->method('dispatch')
@@ -267,13 +268,14 @@ public function testSend($configValue, $forceSyncMode, $isComment, $emailSending
                     'email_invoice_set_template_vars_before',
                     [
                         'sender' => $this->subject,
-                        'transport' => $transport
+                        'transport' => $transport->getData(),
+                        'transportObject' => $transport,
                     ]
                 );
 
             $this->templateContainerMock->expects($this->once())
                 ->method('setTemplateVars')
-                ->with($transport);
+                ->with($transport->getData());
 
             $this->identityContainerMock->expects($this->once())
                 ->method('isEnabled')
@@ -353,7 +355,7 @@ public function sendDataProvider()
             'Successful sync sending without comment' => [0, false, false, true],
             'Failed sync sending with comment' => [0, false, true, false],
             'Successful forced sync sending with comment' => [1, true, true, true],
-            'Async sending' => [1, false, false, false]
+            'Async sending' => [1, false, false, false],
         ];
     }
 }
diff --git a/app/code/Magento/Sales/Test/Unit/Model/Order/Shipment/Sender/EmailSenderTest.php b/app/code/Magento/Sales/Test/Unit/Model/Order/Shipment/Sender/EmailSenderTest.php
index 914385950bbf8..4cc068a2a6209 100644
--- a/app/code/Magento/Sales/Test/Unit/Model/Order/Shipment/Sender/EmailSenderTest.php
+++ b/app/code/Magento/Sales/Test/Unit/Model/Order/Shipment/Sender/EmailSenderTest.php
@@ -262,6 +262,7 @@ public function testSend($configValue, $forceSyncMode, $isComment, $emailSending
                 'formattedShippingAddress' => 'Formatted address',
                 'formattedBillingAddress' => 'Formatted address',
             ];
+            $transport = new \Magento\Framework\DataObject($transport);
 
             $this->eventManagerMock->expects($this->once())
                 ->method('dispatch')
@@ -269,13 +270,14 @@ public function testSend($configValue, $forceSyncMode, $isComment, $emailSending
                     'email_shipment_set_template_vars_before',
                     [
                         'sender' => $this->subject,
-                        'transport' => $transport,
+                        'transport' => $transport->getData(),
+                        'transportObject' => $transport,
                     ]
                 );
 
             $this->templateContainerMock->expects($this->once())
                 ->method('setTemplateVars')
-                ->with($transport);
+                ->with($transport->getData());
 
             $this->identityContainerMock->expects($this->once())
                 ->method('isEnabled')