We are in the process of migrating to Exchange. We are a small IT shop, and would like to work with the system before migrating. We currently have a Sendmail server, for whatever it helps with the question.
My question is this, can we configure Exchange to deliver email to both the Exchange mailboxes and the Sendmail system? Our Sendmail system uses gate.domain.com. We are shortening that to domain.com with Exchange. The idea is that we flip the MX records to start delivering to the Exchange server over the weekend while our users still use the Sendmail system. That way they have pre-populated mailboxes when we migrate, and we are able to test a fully function system in advance of migrating everyone.
Does that make sense?