Requested action not taken: mailbox unavailable NDR When You Send E-Mail Outside Exchange

Microsoft Exchange Server 2007 will reach end of support on April 11, 2017. To stay supported, you will need to upgrade. For more information, see Resources to help you upgrade your Office 2007 servers and clients.

This topic describes how to troubleshoot a non-delivery report (NDR) message that occurs when you try to send an e-mail message to an e-mail address that includes a special character. For example, the address may include an apostrophe (').

When you try to send an e-mail message to a recipient outside a Microsoft Exchange organization, and the e-mail address includes a special character, you may receive the following NDR message:

To resolve this issue, do not include the special character in the e-mail address.