Okay - looking healthier now in terms of receiving. I can run a domain report and can interrogate your server : ) I would imagine sending is a little happier, but some issues to address.
Your server FQDN is exchange.yourdomain.local. This needs to be changed to mail.yourdomain.org and ths is done on the SMTP Virtual Server properties, Delivery Tab, Advanced Button.
Then call SBC Global and ask them to setup Reverse DNS on your fixed IP address with mail.yourdomain.org and then you should be much healthier.