Signup Confirmation Email not sent after PayPal payment

User can pay for product with PayPal, and if user follows the directions in the browser, registration can be completed, user can set password, and the email to confirm the registration and set password is sent. However, the Signup Confirmation Email that includes the registration link and the product purchased is not being sent. I installed WP Email Logging plugin which confirms that this email isn’t being sent. I assume the email system is correct since Wordpress sends an email to confirm the registration. The problem is that the Signup Confirmation Email isn’t sent. What am I missing? Thanks.