Okay. I need some help on this, because I am out of ideas. I have Exchange 2003 in a single server setup for RPC over HTTP (back-end proxy, DC, Exchange all on same box). I have my main domain abc.com and also a few hosted domains def.com, ghi.com, etc. all on the same box. The hosted domains are in separate OUs. I have been using OWA with no problem, but now one of my hosted domains wants to use RPC over HTTP. It seems to work with abc.com users, but none of the other hosted domains. What am I missing here? Each domain has their own GAL and no permissions to the other domain's GALs and I'm thinking this is the problem, but I'm not exactly sure what and how to fix. Any help would be greatly appreciated. Edited to add: I forgot to mention that the error message I am getting on the client side is "The name could not be matched to a name in the address list".