It's possible Openforce fixed the problem, but it looks like a DNS resolution error on your end.
Basically, your SMTPD is saying it couldn't do a reverse lookup on 208.184.248.88, which for me at the moment does resolve.
If you're trying to get Postfix to run in a chrooted environment, I hear you have to take extra steps to get reverse DNS lookup to work.
Also, be aware that if you reject mail from servers that don't have a reverse lookup in DNS you're going to reject a lot of legit email along with the SPAM. It's a sad fact that many networks have broken reverse DNS delegation.
