Wordpress: Send Email after any Post type status change

functions.php

//https://codex.wordpress.org/Post_Status_Transitions
//send email to admin after user create new deal from frontend form.

add_action('future_to_pending', 'send_emails_on_new_event');
add_action('new_to_pending', 'send_emails_on_new_event');
add_action('draft_to_pending', 'send_emails_on_new_event');
add_action('auto-draft_to_pending', 'send_emails_on_new_event');


add_action('pending_to_publish', 'send_emails_on_deal_publish');

 
/**
 * Send emails on event publication
 *
 * @param WP_Post $post
 */
function send_emails_on_new_event($post)
{
    $emails = "[email protected]"; //If you want to send to site administrator, use $emails = get_option('admin_email');
    $title = wp_strip_all_tags(get_the_title($post->ID));
    $url = get_edit_post_link( $post->ID, $context );
    $message = "New Deal Created on Site Name!. Review and Publish. \n Link to post: \n{$url}";
 		if(get_post_type($post->ID) === 'deal') //post, page, attachment or whatever other CPT you may have
	{
    wp_mail($emails, "New Deal Created on Site Name: {$title}", $message);
	}
}   

function send_emails_on_deal_publish($post)
{
  
		$author_id=$post->post_author;
    $emails = get_the_author_meta( 'user_email' , $author_id ); ; //If you want to send to site administrator, use $emails = get_option('admin_email');
    $title = wp_strip_all_tags(get_the_title($post->ID));
    $url = get_permalink( $post->ID );
    $message = "Your Deal is Live.\n Check Deal: \n{$url}";
 		if(get_post_type($post->ID) === 'deal') //post, page, attachment or whatever other CPT you may have
	{
    wp_mail($emails, "Your Deal on Site Name is Live: {$title}", $message);
	}
}