Customizing WordPress User Registration Email

email.php

<?php

function custom_registration_email($user_id) {
  $user_info = get_userdata($user_id);
  $to = $user_info->user_email;
  $subject = 'Welcome to our site!';
  $message = 'Dear ' . $user_info->display_name . ',<br /><br />';
  $message .= 'Thank you for registering on our site. Here is your login information:<br />';
  $message .= 'Username: ' . $user_info->user_login . '<br />';
  $message .= 'Password: Your chosen password<br /><br />';
  $message .= 'If you have any questions, please contact us.<br /><br />';
  $message .= 'Best regards,<br />';
  $message .= 'The Site Team';
  $headers = array('Content-Type: text/html; charset=UTF-8');
  wp_mail($to, $subject, $message, $headers);
}
add_action('user_register', 'custom_registration_email');