I have installed an Exchange 2007 server into our existing organization which previously had one Exchange 2003 server. I followed the microsoft best practices as far as prepping the domain and preparing for the install. The initial install went off without a hitch, I selected our existing ex2k3 server as the bridgehead and joined it.
Right off the bat I could see the Exchange 2003 users from 2k7 and could succesfully move a test user from 2k3 to 2k7. Once that was in place I could then send email from the 2k3 user to the 2k7 user but could not send from 2k7 to 2k3 or from 2k7 to external. I configured a send connector to deliver messages to the internet, and can now send messages to external users from the ex2k7 user but still cannot recieve from external.
In addition we have a Barracuda in place that recieve external email then passes it to our internal Exchange 2003 server on an alternate port.
I had to modify the Internet - Ex2k7 connecter in the defaul administrative group connectors tab to allow recipt from that port as well
On the default admin group as well as the the FYDIBOHF23SPDLT group from the Exchange 2k3 console I am unable to modfiy the connectors to allow delivery to that alternate port ( I am not sure if that is what I need to do or not.)
To summarize my issue is that I can send from an Ex2k3 user to an Ex2k7 user but not from Ex2k7 to Ex2k3, I can also send from Ex2k7 to external but cannot send from External to Ex2k7..