The Microsoft Exchange System Attendant service (Mad.exe) crashes intermittently in the Oabgen.dll module on a Microsoft Exchange Server 2007 server. Additionally, the following events are generated in the Application logs:
This problem occurs because of an antivirus application that scans the public folders. The application scans the Offline Address Book (OAB) messages in the public folder store and removes the OAB attachments. This causes exceptions in the OAB generation process. Therefore, the Mad.exe process crashes.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.