We have exchange 2007 installed with all roles installed on that server. Now we want to Migratie exchange 2013 and we installed exchange server 2013 with all roles on another server. After that I wanted to test the mailflow internally between the 2 exchange servers, but the users from exchange 2007 can't send emails to the exchange 2013 users and the other way around. Any suggestions what is causing this issue?
Kind regards,
Litrick