gistfile1.txt

function send_bonus_email( $form_id, $user_data, $user_id ) 
{
    global $service_locator;
    
    $firstName   = $user_data['first_name'];
    $lastName    = $user_data['last_name'];
  
    $email_content = "
Hey there $firstName, Welcome to WPMUDEV. "\r\n"

Welcome to the club! As a bit of a thank you for taking the time to sign up, here a couple of bonuses 

…"

}

add_action(‘after_signup_user’, ‘send_bonus_email’);