An odd problem occured today on my exchange environment. I had some users complain that they lost connection to exchange. During the time specified I see in the event logs error 4999 and 6004. in researching this I find this KB: KB2600835

Now the KB refers to Exchange 2010 but I am wondering if this i also an issue in Exchange 2013.

Any input?

Hi Patrick,

If the issue occurs when you access mailbox via outlook, I recommend you firstly check if these users can access their mailbox via OWA. If they can, the Exchange Server is ok and maybe there is something wrong with their outlook. Secondly, I recommend you verify the outlook version these users use for further research.

What's more, the KB2600835 isnt applied to Exchange 2013. Because there is no rpc client access service in Exchange 2013.

Hope it helps. If your need further assistance, please feel free to let me know.

Best regards,
Amy