We didn't receive the confirmation email

I have it set up so all my registrants and myself are receiving emails for confirmation purposes. The email did not send but I have a complete registration with payment received. Just wanted to understand how I can fix the problem, and send another email so they have a confirmation themselves.

Are you referring to the autoresponder email or the notification email? If autoresponder email, I checked your email settings and it is configured properly. Please provide the email addresses that didn't receive the autoresponder email so we can check it further. 

We'll wait for your reply.