Move plugin files to a subfolder

[MAILPOET-3988]

mailpoet/lib/Mailer/Methods/ErrorMappers/ConnectionErrorMapperTrait.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace MailPoet\Mailer\Methods\ErrorMappers;
+
+use MailPoet\Mailer\MailerError;
+
+trait ConnectionErrorMapperTrait {
+  public function getConnectionError($message) {
+    return new MailerError(
+      MailerError::OPERATION_CONNECT,
+      MailerError::LEVEL_HARD,
+      $message
+    );
+  }
+}