We are running Exchange 2003. I have a single SMTP Virtual Server and a number of routing connectors. I have one that routes all email to the Internet and two others that route email to specific domains. The later two belong to partners of ours with whom we have a direct network connection so the email never goes to the Internet. Our outgoing email goes to our email filtering service and then on to the recipient. I want to establish a TLS connection with the filtering service, but not with the partners.
I have installed a certificate on our SMTP V/S. I went to the routing group and activated TLS. I have also gone to the SMTP V/S on outbound security and activated TLS. I then wen to our filtering service and turned on TLS as the only want to process outbound email. When I send an email out to an Internet address, it goes just fine and I can see with Wireshark that the body text of the message is unreadable. I have also confirmed that I can send emails to our partners who don't support TLS and whose connectors I have NOT activated TLS. Using wireshark I can see that I am able to read the body text of those emails. I have also confirmed that I can receive emails in from those partners. Currently I have the filtering service set to deliver emails to us just using SMTP...and that works OK. However, when I configure the service to send via TLS only, I am unable to receive emails from the Internet into my Exchange server.
Does anyone have any idea what I've done wrong?