Assume that you enable the attachment filtering feature on a Microsoft Exchange Server 2010 Edge Transport server. The Edge Transport server receives an email message that has a large and complex attachment of a known file type (for example, a PowerPoint presentation). While Exchange Server 2010 Transport processes the email message, the EdgeTransport.exe process consumes 100 percent of CPU resources. Additionally, the Edge Transport server stops responding.
Note This issue also occurs in an Exchange Server 2007 environment.
To resolve this issue in an Exchange Server 2010 environment, install the following update rollup:
2579150 Description of Update Rollup 4 for Exchange Server 2010 Service Pack 1
To resolve this issue in an Exchange Server 2007 environment, install the following update rollup:
2509911 Description of Update Rollup 4 for Exchange Server 2007 Service Pack 3
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about the attachment filtering feature, visit the following Microsoft website: