Associating Exchange 2000 Mailboxes with External Domain Accounts

Migration Wizard gives you the option of associating Exchange 2000 mailboxes with accounts on an external domain and of creating new accounts in the external domain.

Note   The external domain is always either a Windows NT 4.0 domain or a Windows 2000 domain in a separate forest.

When you migrate your existing mail system to Exchange 2000, there must be an object in Active Directory for every mailbox you migrate. However, you might want to allow accounts on an external domain to access Exchange 2000 mailboxes. When, from Migration Wizard's Account Options, you select Associate with accounts in an external domain, Migration Wizard searches the external domain for a Windows NT 4.0 or Windows 2000 account with a logon identifier (ID) that matches the mailbox ID of the migrating mailbox. Then, one of the following occurs:

• If an account with a logon ID matching the mailbox ID is found, Migration Wizard creates a disabled user object in Active Directory for the Exchange 2000 mailbox and creates an association with the account in the external domain.
• If an account with a logon ID matching the mailbox ID is not found, and the Create new accounts in external domain check box is selected, Migration Wizard creates a new account in the external domain, creates a disabled user in Active Directory for the Exchange 2000 mailbox, and then creates an association with the account in the external domain.
• If an account with a logon ID matching the mailbox ID is not found, and the Create new accounts in external domain check box is not selected, Migration Wizard follows the standard process for creating an account in Active Directory.

The Associate with accounts in an external domain option is helpful when:

• You have an existing Windows NT 4.0 domain. You want to keep the user accounts that reside on this Windows NT 4.0 domain but allow users to access Exchange 2000 mailboxes.
• You have multiple forests, including a Windows 2000 domain that is not in the same forest as Exchange 2000. You want to keep the user accounts that reside on the external Windows 2000 domain but allow users to access Exchange 2000 mailboxes.

Example