I am trying to understand if it is possible to have a hosted CRM environment that utilises an 'alien' exchange server. The scenario is that the Company hosts the CRM on their servers and the customer buying that hosting solution requires the CRM to integrate with their own native Exchange Server onsite at their premises. The considerations will be : the alien domain, the hosted CRM configuration and the role of the Email router in all of this. I can find little to no information on this scenario and I was wondering if anyone else has tried the same approach. The other possibility is to replicate the 'alien' exchange and host the replication in the same domain as the CRM installation but this seems awfully clumsy, not to mention expensive.