Emails can get lost or held up in cyberspace. Has happened to me plenty of times.
As far as KOA disappointments, most KOA's are privately owned. Some are down right terrible and some are very very nice and pleasant. We have had many great experiences at KOA's as well as many disappointments.
As another poster stated once KOA has your email you get lots of emails. If your friends are like me you Trash with out reading. If you empty your trash frequently you will never see it.
One typo can send email into cyberspace.
When you had email sent to your friends account, you lost control of your situation. No way of verifying receipt unless you contacted them or waiting for their thank you.