First, check your spam folder to make sure the email wasn’t flagged and sent there automatically. If you still can’t find it, add GoToWebinar.Notifications@logmein.com to your approved email addresses and try registering again.
If this doesn’t work, contact GoToWebinar at 1-833-851-8340 and ask them to check their “Bounce List” list to ensure your email address is not on it. When GoToWebinar receives three undeliverable emails back from an email address their system automatically adds the email to this list, and no longer sends emails to it. If your email is on this list, ask them to remove it.