421 4.3.2 Service not available, closing transmission channel RRS feed

  • Question

  • hi fellows

    i have got an exchange 2007 sp1 running on server 2003,it is sending and receiving emails but when i telnet port 25 i get the following error,(421 4.3.2 Service not available, closing transmission channel)i have searched all the article reference to the same error but no solutions which i can suspect is causing the problem,i have got 3 drives c:d:e and both of them have enough space,can someone help that??i will appreciate.

    Saturday, October 1, 2011 1:37 PM

All replies

  • If everything is working, then Im not sure what the concern is.

    Telneting on port 25 to the Exhcange Server is not necessarily a good test since you may have ip restrictions or permissions set on the connectors.

    Is there is a problem or issue you are trying to solve?


    Saturday, October 1, 2011 1:47 PM
  • the only issues i have now is,i have got forensic email archiving server,all the emails inbound and outbound supposed to go throe the server and is not happening,there is a send connectors configured for email archiving with the cost of 1,my concern is the error what i am getting should be causing the emails not to go throe the archiving server.from exchange and local machines i can telnet mail archiving successfully
    Saturday, October 1, 2011 2:17 PM
  • Are you taling about journaling or achiving, not sure what product youre using but if an internal>internal message is sent then now would that be captured? 

    All traffic would go via the HUB server.

    Do you have journaling configured?

    Can you telnety from the archiving server to the HUB?

    Saturday, October 1, 2011 6:48 PM
  • Hello,


    Do you also receive the “The maximum number of concurrent connections has exceeded a limit” error?


    If so, you can try the following command to raise the limitations:


    Set-ReceiveConnector -Identity "ServerName\Allow to Relay" -MaxInboundConnection 10000
    Set-ReceiveConnector -Identity " ServerName\Allow to Relay" -MaxInboundConnectionPercentagePerSource 50




    Monday, October 3, 2011 7:56 AM
  • thanks guys

    i had few send connectors both of them were not working including the email branding,still cant telnet port 25 from local but as andy said,i will not worry much for now as long as long as the emails are flowing.


    to simon,i have seen that before but managed to sort that one out,thanks a lot guys.

    Tuesday, October 4, 2011 8:12 AM