MAGETWO-91555: Admin orders can result in a customer with an example email address

Author: Joan He

app/code/Magento/Sales/Block/Adminhtml/Order/Create/Form/Account.php

@@ -147,7 +147,7 @@ protected function _addAdditionalFormElementData(AbstractElement $element)
     {
         switch ($element->getId()) {
             case 'email':
-                $element->setRequired(0);
+                $element->setRequired(1);
                 $element->setClass('validate-email admin__control-text');
                 break;
         }

app/code/Magento/Sales/Model/AdminOrder/Create.php

@@ -2012,26 +2012,13 @@ protected function _validate()
     }
 
     /**
-     * Retrieve or generate new customer email.
+     * Retrieve new customer email.
      *
      * @return string
      */
     protected function _getNewCustomerEmail()
     {
-        $email = $this->getData('account/email');
-        if (empty($email)) {
-            $host = $this->_scopeConfig->getValue(
-                self::XML_PATH_DEFAULT_EMAIL_DOMAIN,
-                \Magento\Store\Model\ScopeInterface::SCOPE_STORE
-            );
-            $account = time();
-            $email = $account . '@' . $host;
-            $account = $this->getData('account');
-            $account['email'] = $email;
-            $this->setData('account', $account);
-        }
-
-        return $email;
+        return $this->getData('account/email');
     }
 
     /**