I have inherited this network. It has two domains. The larger domain is win2003 and has exchange 2003, the other is win 2000 and much smaller. I have users whose primary domain is the 2000 domain. All thier file and print and apps are there. But they use the larger domain for exchange. That has been a real hassle since each user has to login twice, once on the 2000 domain, then again to use outlook and exchange. Helping the users know which login to use and what password has been difficult. Also they user multiple conmputers so multiple outlook profiles are often being created. And they work three shifts but I am the only one supporting them. I know i could use roaming profiles, but out look is really the only issue they are running into with multiple computers. Plus roaming profiles have their own issues.
I tried to get around some of these issues by give the users on the 2000 domain rights in AD to the corresponding account in 2003's email accounts. It worked great except for sending mail. It gives the "cannot send on behalf of" error message. They can open and read but not send. Does any one have a solution for this. I checked AD and there is a feature for send on behalf of...but it only accepts users from the 2003 domain, not the 2000 domain. (though there is a trust between the two)
The good news is I am migrating the users into one domain, but that takes time.