If your attendee didn't receive their certificate, verify that they are checking the email that they registered with, and then have them check their spam/junk folder. It's possible that their email client filtered out your follow-up email or that your company's servers might have blocked the email due to security firewalls. Unfortunately, certificates cannot be resent at this time. If you are the attendee and need further help after checking these things, contact your organizer directly. See Contact the organizer of the webinar for more information.