- You have an Active Directory Domain Services (AD DS) multi-domain environment.
- In this environment, Active Directory user accounts are located in a different AD domain than the AD domain in which Microsoft Exchange Server 2016 is installed. For example, Exchange Server 2016 is installed in Child.Contoso.com and user accounts are located in contoso.com.
Additionally, users receive the following error message:
'contoso.com/Users/A2' couldn't be found on
- Log in to ECP.
- On the Options menu, expand Mail, and then click Other.
- Click Go to the earlier version.
Article ID: 3124055 - Last Review: Jan 26, 2016 - Revision: 1