We have exchange 2010 and last friday our outgoing email started to be blocked by spamhaus and prs. I do not know why this is as I had changed nothing. The error is 550 and the ip it's showing is the our external internet ip not the external ip for exchange. We use Forefront-TMG as a firewall. incoming email works fine. Where do I look to find the settings I need? I am a new user with this product.
Annette Zacharias