Attachment Rules for SMTP Filter May Become Damaged

When you refresh after you create attachment rules for the SMTP Application filter, the attachment rules may be missing, and may have been replaced with a red X.

This problem can occur when two or more of the attachment rules have the same value.

This problem was corrected in Internet Security and Acceleration Server Service Pack 1.

For additional information, click the article number below to view the article in the Microsoft Knowledge Base:

To work around this problem, do not use the same value for 'Attachment name' and 'Attachment extension' or 'Attachment file size' when you create attachment filters.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

You can use the SMTP Application filter in ISA Server to filter attachments in SMTP traffic based on any of the following:

• Attachment name
• Attachment extension
• Attachment size limit

Only one of the preceding criteria can be specified in one rule. If two or more rules have the same value, the rules no longer function, and are replaced with a red X. For example: Even though the preceding rules have differing criteria for filtering attachments, they both have the same value of ".exe".