By default, there is no option to add Dynamic Content in a contact form field. Because of that, you cannot display the Post/Page's title from where a Contact Form module was submitted.
This article provides all the customization steps to implement the Post/Page's title in the Contact Form module's Email body.
- For each Contact Form module that you want to include the Post/Page's title in the Email's body, open its setting by clicking on the Gear icon  
- Insert a new Field and set the following options: 
- Go to Advanced Tab β Custom CSS β Free Form CSS 
- Add this CSS code: - selector {
 display: none;
 }
 The CSS code will hide the field from the front end since we don't actually need to display it.
- Edit the Message Pattern and make sure the field is included by using %%dt-custom-title%% 
- If you are using a Child theme, edit the functions.php file and place this PHP code after the existing code: - // Add current post title to a contact form hidden field 
 function add_post_title_to_cf_field(){
 // Get post title
 global $post;
 $title = get_the_title($post->ID); ?>
 <!-- Script for adding the retrieved title into the hidden field -->
 <script>
 (function($){
 $(document).ready(function(){
 if ($('p[data-id="dt-custom-title"] input').length) {
 $('p[data-id="dt-custom-title"] input').attr('value','<?php echo $title; ?>');
 }
 });
 })(jQuery);
 </script>
 <?php }
 add_action('wp_footer', 'add_post_title_to_cf_field');
Note: if you are not using a Child theme, you can install and activate the Code Snippets plugin. The above PHP code can be added as PHP Snippet.
The result can be seen in the screenshot below:





