An e-mail message recipient cannot use a Web-based e-mail client to access an attachment when the message is sent by using Exchange 2007

An e-mail message that contains an attachment is sent by using Microsoft Exchange Server 2007. When the message recipient uses a Web-based e-mail client to access his or her mailbox, the recipient cannot access the attachment.

Note The recipient can access the attachment if the message is sent by using Microsoft Exchange Server 2003.

This problem occurs because Exchange 2007 incorrectly sets the size parameter of the attachment to 0. This value does not align with RFC 2183. When the size parameter of the attachment is set to 0, some Web-based e-mail clients treat the attachment as nonexistent.

To resolve this problem, install Update Rollup 5 for Exchange Server 2007. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

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