Fixes #1: Adding compatibility with Magento 2.2

Model/Transport.php

@@ -65,4 +65,12 @@ public function sendMessage()
             throw new \Magento\Framework\Exception\MailException(new \Magento\Framework\Phrase($e->getMessage()), $e);
         }
     }
+
+    /**
+     * @inheritdoc
+     */
+    public function getMessage()
+    {
+        return $this->_message;
+    }
 }

composer.json

@@ -1,6 +1,7 @@
 {
   "name": "codepeak/magento2-mailtrap",
   "description": "Enable mail testing through Mailtrap.io",
+  "version": "1.1.0",
   "license": "proprietary",
   "authors": [
     {
@@ -9,7 +10,9 @@
     }
   ],
   "minimum-stability": "dev",
-  "require": {},
+  "require": {
+    "magento/module-email": "*"
+  },
   "autoload": {
     "files": [
       "registration.php"

etc/di.xml

@@ -1,4 +1,4 @@
 <?xml version="1.0"?>
 <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
-    <preference for="\Magento\Framework\Mail\Transport" type="Codepeak\Mailtrap\Model\Transport"/>
+    <preference for="Magento\Framework\Mail\TransportInterface" type="Codepeak\Mailtrap\Model\Transport"/>
 </config>

etc/module.xml

@@ -1,4 +1,8 @@
 <?xml version="1.0" ?>
 <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
-	<module name="Codepeak_Mailtrap" setup_version="1.0.0"/>
+	<module name="Codepeak_Mailtrap" setup_version="1.1.0">
+		<sequence>
+			<module name="Magento_Email"/>
+		</sequence>
+	</module>
 </config>