Our company is in the process of acquiring another firm of around 50 employees. Their network setup is very unique. This is presenting an issue for the quick turn around time that I have been given to get them on our email system. The thing that is most important to the powers that be that happen immediately is that they be able to view our intranet and are on our email system in outlook. Intranet is easy and done. We basically created an IPSEC tunnel between them and our office and added the our intranet servers host information into their internal DNS, set permissions on our intranet server and it works fine. The issue is with the email. I am at a loss on the best way to make this happen. (keeping in mind that this will not be a permanent fix)
Typically, with these acquisitions, we would bring in a domain controller (on our domain) and exchange server, rejoin all users to our DC, repoint their MX records to our exchange server, move over their email to our exchange server and we would be good to go. Due to the complex setup of their system and timeframe, this is not possible at this time.
I am looking for ideas on how to get the email working for them on a temp basis until the time comes to do the true domain setup mentioned above. They currently have their own domain with an exchange server. Keep in mind that we have a secure tunnel setup between them and us.
One of my thoughts was to:
Create all user accounts and mailboxes (need to do either way) on our domain / forward all of their incoming emails to the newly created email addresses (our domain) to their existing email addresses on their exchange server (so they can receive emails to the new email addresses (incoming) on there existing exchange server / creating an smtp email address on their existing exchange to our domain and setting it as the primary email address / have the connector on their end use a smart host the would point to one of our exchange servers (for outgoing emails). Not sure that this will work on the outgoing side of things