Event ID: 4999 Source: MSExchange Common

Event: 4999
Agent Time: xxx
Event Time: xxx
Source: MSExchange Common
Category: General
Username: N/A
Computer: xxx
Description: Watson report about to be sent to dw20.exe for process id: 4924, with parameters: E12, c-RTL-AMD64, 08.01.0375.002, edgetransport, M.E.Transport, M.E.T.D.DumpsterComponent.DeleteDumpsterItem, System.NullReferenceException, 95a7, 08.01.0375.002. ErrorReportingEnabled: True

On a Microsoft Exchange Server 2007 server, after you set the value of the CalendarItemRetrievalOption parameter to Custom for the IMAP4 service, you may find that the IMAP4 service crashes intermittently. When this problem occurs, all IMAP clients cannot access their mailboxes.



install Update Rollup 7 for Microsoft Exchange Server 2007 Service Pack 1

source: http://support.microsoft.com/kb/960384/