Exchange 2013 SP1 Breaks Hub Transport service

I had an issue last night that woke me up at 2 am in the morning by the On Call phone. I feel that we might see this often when Exchange admins start to applying Exchange server 2013 SP1.

After installing Exchange 2013 sp1, MSExchange Transport service hangs at “Starting”, then eventually crashes with couple of event ID’s.

“Event ID 1046, MSExchange TrasnportService

Worker process with process ID 17836 requested the service to terminate with an unhandled exception. “

“Event ID 4999, MSExchange Common

Watson report about to be sent for process id: 2984, with parameters: E12IIS, c-RTL-AMD64, 15.00.0847.032, MSExchangeTransport, M.Exchange.Net, M.E.P.WorkerProcessManager.HandleWorkerExited, M.E.ProcessManager.WorkerProcessRequestedAbnormalTerminationException, 5e2b, 15.00.0847.030. “

Only way to get Transport service to start, is to disable all receive connectors and reboot the server. Does it sound familiar? My colleague Andrew Higginbotham  wrote this article few weeks ago. Although it was a different issue, but custom receive connectors on a multirole server is the key.

In my case, this is also a multirole server(CAS and Mailbox on one box).  Hub Transport service listens on TCP port 2525, and Frontend transport listens on TCP port 25.  There are two custom receive connectors that were created with Hub Transport role. Both are listening on TCP port 25. I’m not sure why they haven’t had external mail flow issue by now, but it sure knows how to get your attention by breaking the transport service.

If we disable both custom receive connectors, transport service starts fine. So we went ahead and changed transport role from Hub Transport to Frontend Transport on both connectors with Set-ReceiveConnector powershell cmdlet, then re-enable them to test. Hub Transport service stays up without issue. Of course, we also rebooted the server to make sure that issue is fixed.



Edit. Microsoft has released the following KB addressing the issue


11 thoughts on “Exchange 2013 SP1 Breaks Hub Transport service

  1. Pingback: NeWay Technologies – Weekly Newsletter #84 – February 28, 2014 | NeWay

  2. Pingback: Exchange 2013 SP1 Transport Issue | Just A UC Guy

  3. OMG! THANK YOU!!! I updated exchange 2013 to sp1 and the transport service would not start for anything. After hours of research i came across this and indeed it worked! Thanks once again.

  4. Good Find 🙂 Thanks a Mill, All I did was disable a custom receive connector(For Scan to email for printers) and the services started. Man this SP1 has caused allot of grief with 4 Servers I just upgraded. Last of the few issues though thanks again 🙂

  5. My transport service is started but I am not getting any external mail, it bounces back, I restart the transport service and it works for a few minutes! After disabling my custom receive connector (Hub Transport), everything works fine. I delete and re-create the receive connector as a Front End, but then my Scan to Email is not working. If I change it back to a Hub Transport, it works fine. Any ideas?

    • so,this is after SP1 was installed? it’s surprising that when you configured a custom receive connector as FrontEnd Transport, mail is not working. Did you double check the permission, port, and IP scope?

  6. Pingback: Служба «Microsoft Exchange Transport» неожиданно прервана. Не запускается служба транспорта | IT in realworld

  7. I have a similar issue, just discovered that external emails are bouncing back. Now there are two Hub receive connectors one listening on port 2525 another on port 465. And there are three front end receive connectors, only one listens on 25, but every time the front end service fails with complaints that 25 is in use. Only when I disable this connector with port 25 is when service runs, but I can’t get external emails. Am very stuck.

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