Our main Domain abc.com, is configured in Exchange 2007, this is our primary email server. We recently purchased a separate domain. for a small project that the execs are working on. We have this domain being forwarded straight from "Go Daddy" to each of their individual email addresses.
Example: firstname.lastname@example.org (new domain) to email@example.com (existing account here).
The problem is that when they reply they are replying with firstname.lastname@example.org (existing account here) not the new domain.