Add custom shortcodes to Wordpress emails - By WebToffee( Decorator – WooCommerce email customizer )

functions.php

<?php //Do not copy this line of code
add_filter('wt_woomail_no_order_body_text','wbtf_add_custom_placeholder_to_user_emails',10,2);
function wbtf_add_custom_placeholder_to_user_emails($body_text, $email) {
  if ( is_a( $email->object, 'WP_User' ) ) {
		$body_text = str_replace( '{custom_value}',  'Actual data to replace', $body_text );  // Replace placeholder and value here
  }
  return $body_text;
}