Generally, if your customer is not receiving an email notification there are a few things that can be checked. The first is to make sure that the email notification is not being sent to their spam folder. We recommend that they add recurly.com to their safe list in their email spam configuration, for better delivery. Additionally, they will want to check with their email provider to determine if there is any additional filtering on their side that is preventing the emails from reaching their inbox. You can also reach out to our support team who is always happy to review the accounts in question to confirm if the email notifications were in fact delivered to your customer.