Hi,

 I have installed Ex2013 on a separate box.  Over the weekend I have switched the 2010 CAS role to my new CAS server.  I update the external url's on the virtual directories on the new CAS server swapped out the ip's of my 2010 exchange putting it on the new one (as I don't have to make any changes to my public dns records) and set a new ip for my 2010 cas box with mailboxes.  Last, I updated the internet connector to include my new CAS server as a source server.  Basiscally, everything works fine except the now we can't send any external emails.  We got an undeliverable message saying that "client host x.x.x.x blocked using block list 1, mail from IP banned............