I'm migrating an source AD forest, forest A, with Exchange 2007, SP3 with latest or 2nd latest rollup, into a different target forest, forest B, with Exchange 2010, SP3 not sure of rollup without looking. I'm in the early steps setting up the mail flow and SMTP sharing.
Receive Connectors: Both systems have "Anonymous Users" and the IPs setup for the HT servers in the opposite forest.
Send Connectors: Both the source and target forests have a send connector for *all* SMTP suffixes for the source forest, A. They contain default settings, have proper source servers and the address spaces are added with a cost of 1 and "Include all subdomains" checked.
Accepted Domains: Source forest, A, has been converted from Authoritative to Internal Relay for all SMTP address spaces. Target forest, B, has all the accepted domains added to it as Internal Relay.
I added a source forest, A set of email addresses to a test user on the target forest, B. When sending internally or externally, a response of the user not existing comes from the source forest's, A, HT server(s). This shouldn't be possible in Internal Relay... it should forward it to the target forest, B.
Anyone have any ideas why the source forest, A, is still treating the domains like it's Authoritative?