Email To client doenst work ! ( WooCommerce )

It’s possible that your sender email address, or your server, have been blacklisted by the recipient’s mail server. It’s also possible that the customer is receiving the emails, but they are going in the spam folder (it can happen, and a lot of email users don’t check the spam folder unless somebody reminds them to do it).

To prevent this kind of issues, it’s better to use a mail service such as Mandrill. There is a simple plugin for WordPress that integrates with that service seamlessly, it’s called wpMandrill.