After you apply Exchange Server version 5.5 Service Pack 3, you cannot send an Internet mail message that contains an illegal X-Mac-Creator attribute in the mail header. The Internet mail message is archived and Event ID 12006 and Event ID 4117 are displayed in the Windows NT Event Viewer. An illegal X-Mac-Creator attribute is created if you attach Macintosh binary files to some Internet mail applications for Macintosh.
Exchange Server version 5.5 Service Pack 2 and earlier ignored the X-Mac-Type and X-Mac-Creator attributes. Exchange Server version 5.5 Service Pack 3 supports headers that contain these attributes in messages. But if the attributes in these headers contain illegal data format, Exchange Server version 5.5 Service Pack 3 moves the message to the archive folder instead of delivering it.
To resolve this problem, obtain the latest service pack for Exchange Server 5.5. For additional information, click the following article number to view the article in the
Microsoft Knowledge Base:
XGEN: How to Obtain the Latest Exchange Server 5.5 Service Pack
The following files are available for download from the Microsoft
For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:
How to Obtain Microsoft Support Files from Online Services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file.
Microsoft has confirmed that this is a problem in Microsoft Exchange Server version 5.5 Service Pack 3. This problem was first corrected in Exchange Server 5.5 Service Pack 4.