Hi, I have just installed a new Exchange 2010 box in our network which has an Exchange 2003 server. The 2010 box sends through a connector via the 2003 box.
From a mailbox on the 2010 Server, I am able to send mails internally. I cannot send to external addresses.
I have added the 2010 IP addresses to the 2003 Virtual SMTP Server Relay Restrictions list (allowed).