Our company has an Exchange 2010 server pulling email from a POP server that is internet facing. We have users on the POP server as well as on the Exchange server that all share the same domain name. Sending email from either server is no problem, but I can't get Exchange to send to users on the POP server. It always comes back as user unknown, most likely because those users indeed are not on the Exchange server.
Is there a way to get Exchange to send to the users on the POP even though they're on the same domain? I added an SMTP connector that delivers to the POP. I tried setting the accepted domain to 'Internal Relay' but which worked, but then we couldn't deliver locally.
This setup used to work when we had Exchange 2003.