I have an installation of Exchange 2010 SP1 with multi-tenant support enabled via the install time /hosting switch. Everything works well for my smaller clients. I now have a bigger client that has about 300 users and 3 domains. The users are divided roughly equally amongst the domains - ie, 3 domains each with 100 users. I've added the first domain as normal: $c = get-credential New-organization -name "Pretend Company" -DomainName domain1.com -ProgramId HostingSample -OfferId 2 -location en-US -AdministratorPassword $c.password After that I logged into the ECP control panel and created all the users. The migration went smoothly and has been working well for the last week. Now, it's time to add the next domain. Since the client wants all 300 users visible in the same GAL, I just added a domain to the organization: New-AcceptedDomain -Name domain2.com -DomainName domain2.com -Organization "Pretend Company" This is where I run into problems. When I try to create the users for domain2.com via ECP, I am able to create the user successfully, and select domain2.com from the drop down. Once the user is created however, I am able to see that although their UPN is user@domain2.com, it created their email address as user@domain1.com. I tried creating the users manually via EMS: $password = Read-Host "Enter password" -AsSecureString New-MailUser -UserPrincipalName testuser@domain2.com -Password $password -Name "Test User" -Organization "Pretent Company" -PrimarySmtpAddress testuser@domain2.com The user creates successfully and I can see the user created in the proper OU in AD. Unfortunately I can not see them in ECP nor can I see them if I do: get-mailbox -Organization "Pretend Company" This makes the management of the users very difficult to delegate, and I'm not sure that the users at domain2.com will even work. This brings me to my questions: (1) Is is possible create accounts that have different domain names in their default email addresses within the same Organization in /hosting mode? (2) Is this something I need to do with an EmailAddressPolicy? I read the documentation but it didn't seem /hosting friendly.

Hi Earonk, Please post your issue on below forum, you will get more help from there: http://social.technet.microsoft.com/Forums/en-us/exchange2010hosters/threads Regards! Gavin