I have a general contact form that appear in each post of a specific custom post.
I would like that when the user submit the form, in the subject of the email appear the post title of the post where the user submit the form.
Here is the link to my post: hidden link
So I would like that when the user submit the form, in the subject of the email appear the post title for example in that case: "Residencial Parque Azucarera".
For that, you need to create post type that store the "Contact Us" entries submitted from front-end. For example, Create post type "Contacts" and then try to create the form that creates a new entry for this post type and you will be able to set up email notification:
=> https://toolset.com/documentation/user-guides/automated-email-notifications-with-cred/