I would like to know if its possible to have multiple domains (individual Windows 2003 AD forests) connect to an Exchange 2003 organization located on a separate W2K3 AD domain using a Forest Trust alone? I already understand the one exchange org per AD forest is the best way to go; and this can also be accomplished with IIFP or MIIS. However the customer stands firmly that the desired design would be to keep the existing domains separate and find a solution to connect to an existing exchange server in a W2K3 AD domain. No other communication between domains will be necessary. Note: each one of these domains currently have site to site VPNS in place and can resolve via DNS or local IP subnet (i.e. 192.168.x.x) to the existing mail server. Thank you.