421 4.3.2 Service not available RRS feed

  • Question

  • A relatively new installation (3 weeks) of EX2013 and for the last 2 days, every 4-5 hours or so, inbound mail stops. I have checked the event logs and nothing, no errors show. A test through testexchangeconnectivity.com give the error 421 4.3.2 Service not available.

    Whilst a simple restart of the transport service rectifies the issue, I am not sure how to establish what is causing the problem.

    Any suggestions?

    Friday, January 4, 2013 3:22 PM


All replies

  • Hi,
    I haven't seen this problem myself so I don't have a suggestion for you, but I just want you to know that the exact same problem is discussed in the below thread.

    See: http://social.technet.microsoft.com/Forums/en-US/exchangesvradmin/thread/cd03793b-9e99-474e-8f25-11275652882f/

    Martina Miskovic

    • Marked as answer by gjross Friday, January 4, 2013 9:52 PM
    Friday, January 4, 2013 5:47 PM
  • Many thanks - it does seems to be the very same issue so will follow that thread instead.
    Friday, January 4, 2013 9:52 PM
  • Put the local host's (Exchange server) IP address into the Internal Relay receive connector and restart the FrontEnd Transport service.

    I don't know WHY it worked, but it did for me.  It was a "Try it and see what happens" stab in the dark.

    I don't know how long it will last before I have to restart the FrontEnd Transport service again.

    Thursday, May 9, 2013 2:45 PM
  • What is the exact Receive connector you are referring to here in your response that you modified. By default there are 5 connectors created. 


    Friday, February 5, 2016 4:08 PM
  • Could you please elaborate on exactly where I need to add the IP address of the Exchange Server within the receive connectors. 
    Friday, February 5, 2016 4:10 PM
  • You might need a new Receive connector.
    The Network tab has the option to accept email from specific IP addresses and ports. Put the internal IP address into their. 
    Wednesday, January 30, 2019 8:00 AM
  • Thanks @Nate_MCT

    After restarting FrontEnd Transport Service, it got resolved.

    Thursday, September 19, 2019 8:40 PM