Error message when users use an SMTP client to send e-mail messages in Exchange Server 2007 Service Pack 1: "454 4.7.0 Temporary authentication failure"

Consider the following scenario:

• You deploy a Microsoft Exchange Server 2007 Service Pack 1 (SP1) server in an Exchange Server resource forest.
• You create linked mailboxes for some users in the account forest.
• You create a one-way outgoing forest trust for both the Exchange Server resource forest and the account forest domain.

In this scenario, the users of the account forest who have mailboxes on the Exchange Server server in the Exchange Server resource forest cannot send e-mail messages by using the SMTP protocol.

Additionally, if the users use SMTP clients to send e-mail messages, the users may receive the following error message:Note Users do not experience this problem if they use Microsoft Outlook in MAPI (Exchange Server) mode.

To resolve this problem, install Update Rollup 4 for Exchange Server 2007 Service Pack 1 on the Exchange Server server. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

To work around this issue, convert the one-way forest trust to a two-way forest trust.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

For more information about how to deploy Exchange Server 2007 in an Exchange Server resource forest topology, visit the following Web site: For more information about how to create a one-way outgoing forest trust for both sides of the trust, visit the following Web site: