In a Microsoft Exchange Server 2013 environment, the EdgeTransport.exe process starts to crash when PriorityQueuingEnabled in %ExchangeInstallPath%Bin\EdgeTransport.exe.config is set to True.
Note A related event is 4999. This event is associated with the GetExpiryTime function.
Source: MSExchange Common
Message: Watson report about to be sent for process id: 4512, with parameters: E12IIS, c-RTL-AMD64, 15.00.0995.029, edgetransport, M.Exchange.Transport, M.E.T.TransportMailItem.GetExpiryTime, System.AggregateException, 2a72, 15.00.0995.028.
To resolve this problem, install Cumulative Update 9 for Exchange Server 2013.
To work around this problem, set PriorityQueuingEnabled in %ExchangeInstallPath%Bin\EdgeTransport.exe.config to False.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.