I have created Contact template but not display header and footer

Question

I have created Contact template but not display header and footer. below my code for contact html.

<!--@subject {{trans "Contact Form"}} @--> <!--@vars { "var
data.comment":"Comment", "var data.email":"Sender Email", "var
data.name":"Sender Name", "var data.telephone":"Sender Telephone" }
@-->

<!--@vars { "template
config_path=\"design\/email\/footer_template\"":"Email Footer
Template", "template
config_path=\"design\/email\/header_template\"":"Email Header
Template" } @-->

{{template config_path="design/email/header_template"}}

<table>
    <tr>
        <td>{{trans "Name: %name" name=$data.name}}</td>
    </tr>
    <tr>
        <td>{{trans "Email: %email" email=$data.email}}</td>
    </tr>
    <tr>
        <td>{{trans "Phone Number: %telephone" telephone=$data.telephone}}</td>
    </tr>
    <tr>
        <td>{{trans "Comment: %comment" comment=$data.comment}}</td>
    </tr> 
</table>

{{template config_path="design/email/footer_template"}}

Answer 1

Create Files in module 1. Packgesname/modulename/etc/email_templates.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Mypackages_Mymodule:etc/email_templates.xsd">
    <template id="contact_general_template" label="Contact" file="contact_dd.html" type="html" module="Mypackages_Mymodule" area="frontend"/>
</config>

2. Packagesname/modulename/view/frontend/email/contact_dd.html

<!--
/**
 * Copyright © 2013-2017 Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->

 <!--@subject {{trans "Contact Form"}} @--> <!--@vars { 
    "var data.comment":"Comment", "var data.email":"Sender Email", 
     "var data.name":"Sender Name", "var data.telephone":"Sender Telephone",
     "template config_path=\"design\/email\/footer_template\"":"Email Footer Template", 
     "template config_path=\"design\/email\/header_template\"":"Email Header Template"
     }  @-->

{{template config_path="design/email/header_template"}}
<table>
    <tr>
        <td>{{trans "Name: %name" name=$data.name}}</td>
    </tr>
    <tr>
        <td>{{trans "Email: %email" email=$data.email}}</td>
    </tr>
    <tr>
        <td>{{trans "Phone Number: %telephone" telephone=$data.telephone}}</td>
    </tr>
    <tr>
        <td>{{trans "Comment: %comment" comment=$data.comment}}</td>
    </tr>
</table>
{{template config_path="design/email/footer_template"}}

3. override file Magento\Contact\Controller\Index\Post

   $post = $this->getRequest()->getPostValue();
           if (!$post) {
               $this->_redirect('*/*/');
               return;
           }
   

       $this->inlineTranslation->suspend();
       try {
           $postObject = new \Magento\Framework\DataObject();
           $postObject->setData($post);
   
           $error = false;
   
           if (!\Zend_Validate::is(trim($post['name']), 'NotEmpty')) {
               $error = true;
           }
           if (!\Zend_Validate::is(trim($post['comment']), 'NotEmpty')) {
               $error = true;
           }
           if (!\Zend_Validate::is(trim($post['email']), 'EmailAddress')) {
               $error = true;
           }
           if (\Zend_Validate::is(trim($post['hideit']), 'NotEmpty')) {
               $error = true;
           }
           if ($error) {
               throw new \Exception();
           }
       $storeId = $this->storeManager->getStore()->getId();
           $storeScope = \Magento\Store\Model\ScopeInterface::SCOPE_STORE;
           $transport = $this->_transportBuilder
               ->setTemplateIdentifier($this->scopeConfig->getValue(self::XML_PATH_EMAIL_TEMPLATE, $storeScope))
               ->setTemplateOptions(
                   [
                       'area' => \Magento\Framework\App\Area::AREA_FRONTEND,
                       'store' => $storeId,
                   ]
               )
               ->setTemplateVars(['data' => $postObject])
               ->setFrom($this->scopeConfig->getValue(self::XML_PATH_EMAIL_SENDER, $storeScope))
               ->addTo($this->scopeConfig->getValue(self::XML_PATH_EMAIL_RECIPIENT, $storeScope))
               ->setReplyTo($post['email'])
               ->getTransport();
   
           $transport->sendMessage();
           $this->inlineTranslation->resume();
           $this->messageManager->addSuccess(
               __('Thanks for contacting us with your comments and questions. We\'ll respond to you very soon.')
           );
           $this->getDataPersistor()->clear('contact_us');
           $this->_redirect('contact/index');
           return;
       } catch (\Exception $e) {
           $this->inlineTranslation->resume();
           $this->messageManager->addError(
               __('We can\'t process your request right now. Sorry, that\'s all we know.')
           );
           $this->getDataPersistor()->set('contact_us', $post);
           $this->_redirect('contact/index');
           return;
       }
   

Answer 2

Only use

<!--@subject {{trans "Contact Form"}} @--> 
<!--@vars { 
    "var data.comment":"Comment", "var data.email":"Sender Email", 
    "var data.name":"Sender Name", "var data.telephone":"Sender Telephone",
    "template config_path=\"design\/email\/footer_template\"":"Email Footer Template", 
    "template config_path=\"design\/email\/header_template\"":"Email Header Template"
    }
 @-->

Then run

php bin/magento setup:di:compile