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Exchange 2013 SMTP Relay

    Question

  • Exchange 2013 hybrid with Office 365.

    Exchange 2013 is basically just an email relay now.

    Generally it works fine.

    We experience an intermittent issue with an internal line of business application that attempts to relay but cannot.  The application does not provide detailed logs to troubleshoot.

    I retrieved the following from the Exchange protocol logs.  The two events are pretty much the same type of relay, except that one fails with a socket error and one succeeds.

    Is it the business application that is failing, or the Exchange transport?

    --- THIS ONE FAILED ---
    ICLEXC2,08D53DBAFFEDF27F,1,192.9.200.6:25,192.9.200.235:50814,>,"220 ICLEXC2.independentcement.com.au Microsoft ESMTP MAIL Service ready at Wed, 7 Mar 2018 06:06:26 +1100",
    2018-03-06T19:06:27.164Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,2,192.9.200.6:25,192.9.200.235:50814,<,EHLO ICLUDOCS02,
    2018-03-06T19:06:27.164Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,3,192.9.200.6:25,192.9.200.235:50814,>,250  ICLEXC2.INTERNALDOMAIN Hello [192.9.200.235] SIZE 37748736 PIPELINING DSN ENHANCEDSTATUSCODES STARTTLS 8BITMIME BINARYMIME CHUNKING,
    2018-03-06T19:06:27.164Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,4,192.9.200.6:25,192.9.200.235:50814,<,RSET,
    2018-03-06T19:06:27.164Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,5,192.9.200.6:25,192.9.200.235:50814,*,Tarpit for '0.00:00:05' due to '250 2.0.0 Resetting',
    2018-03-06T19:06:32.179Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,6,192.9.200.6:25,192.9.200.235:50814,>,250 2.0.0 Resetting,
    2018-03-06T19:06:32.179Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,7,192.9.200.6:25,192.9.200.235:50814,<,MAIL FROM: <umail@OBSCURED>,
    ---
    2018-03-06T19:06:32.179Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,8,192.9.200.6:25,192.9.200.235:50814,*,08D53DBAFFEDF27F;2018-03-06T19:06:27.039Z;1,receiving message
    2018-03-06T19:06:32.179Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,9,192.9.200.6:25,192.9.200.235:50814,<,RCPT TO:<accounts@INTERNAL DOMAIN>,
    2018-03-06T19:06:32.179Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,10,192.9.200.6:25,192.9.200.235:50814,<,RCPT TO:<OBSCUREDy@EXTERNAL DOMAIN>,
    2018-03-06T19:06:32.179Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,11,192.9.200.6:25,192.9.200.235:50814,<,DATA,
    2018-03-06T19:06:32.179Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,12,192.9.200.6:25,192.9.200.235:50814,>,250 2.1.0 Sender OK,
    2018-03-06T19:06:32.179Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,13,192.9.200.6:25,192.9.200.235:50814,>,250 2.1.5 Recipient OK,
    2018-03-06T19:06:32.179Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,14,192.9.200.6:25,192.9.200.235:50814,>,250 2.1.5 Recipient OK,
    2018-03-06T19:06:32.179Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,15,192.9.200.6:25,192.9.200.235:50814,>,354 Start mail input; end with <CRLF>.<CRLF>,
    2018-03-06T19:06:32.461Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,16,192.9.200.6:25,192.9.200.235:50814,*,,Proxy destination(s) obtained from OnProxyInboundMessage event. Correlation Id:d5bb80a8-d550-4e7c-bd03-151c5c3306e8
    2018-03-06T19:06:33.508Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,17,192.9.200.6:25,192.9.200.235:50814,*,,Message or connection acked with status Retry and response 451 4.4.397 Error communicating with target host. -> 421 4.2.1 Unable to connect -> SocketConnectionRefused: Socket error code 10061
    2018-03-06T19:06:33.508Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,18,192.9.200.6:25,192.9.200.235:50814,>,451 4.7.0 Temporary server error. Please try again later. PRX5 ,
    2018-03-06T19:06:33.508Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,19,192.9.200.6:25,192.9.200.235:50814,<,RSET,
    2018-03-06T19:06:33.508Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,20,192.9.200.6:25,192.9.200.235:50814,>,250 2.0.0 Resetting,
    2018-03-06T19:06:33.508Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,21,192.9.200.6:25,192.9.200.235:50814,<,QUIT,
    2018-03-06T19:06:33.508Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,22,192.9.200.6:25,192.9.200.235:50814,>,221 2.0.0 Service closing transmission channel,
    2018-03-06T19:06:33.508Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF27F,23,192.9.200.6:25,192.9.200.235:50814,-,,Local
    ---
    
    --- THIS ONE WAS OK ---
    2018-03-06T19:06:34.242Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,0,192.9.200.6:25,192.9.200.235:50815,+,,
    2018-03-06T19:06:34.242Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,1,192.9.200.6:25,192.9.200.235:50815,>,"220 ICLEXC2.INTERNALDOMAIN Microsoft ESMTP MAIL Service ready at Wed, 7 Mar 2018 06:06:33 +1100",
    2018-03-06T19:06:34.367Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,2,192.9.200.6:25,192.9.200.235:50815,<,EHLO ICLUDOCS02,
    2018-03-06T19:06:34.367Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,3,192.9.200.6:25,192.9.200.235:50815,>,250  ICLEXC2.INTERNALDOMAIN Hello [192.9.200.235] SIZE 37748736 PIPELINING DSN ENHANCEDSTATUSCODES STARTTLS 8BITMIME BINARYMIME CHUNKING,
    2018-03-06T19:06:34.367Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,4,192.9.200.6:25,192.9.200.235:50815,<,RSET,
    2018-03-06T19:06:34.367Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,5,192.9.200.6:25,192.9.200.235:50815,*,Tarpit for '0.00:00:05' due to '250 2.0.0 Resetting',
    2018-03-06T19:06:39.383Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,6,192.9.200.6:25,192.9.200.235:50815,>,250 2.0.0 Resetting,
    2018-03-06T19:06:39.383Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,7,192.9.200.6:25,192.9.200.235:50815,<,MAIL FROM: <umail@OBSCURED>,
    2018-03-06T19:06:39.383Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,8,192.9.200.6:25,192.9.200.235:50815,*,08D53DBAFFEDF281;2018-03-06T19:06:34.242Z;1,receiving message
    2018-03-06T19:06:39.383Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,9,192.9.200.6:25,192.9.200.235:50815,<,RCPT TO:<accounts@EXTERNAL DOMAIN>,
    2018-03-06T19:06:39.383Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,10,192.9.200.6:25,192.9.200.235:50815,<,RCPT TO:<OBSCURED@EXTERNAL DOMAIN>,
    2018-03-06T19:06:39.383Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,11,192.9.200.6:25,192.9.200.235:50815,<,DATA,
    2018-03-06T19:06:39.383Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,12,192.9.200.6:25,192.9.200.235:50815,>,250 2.1.0 Sender OK,
    2018-03-06T19:06:39.383Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,13,192.9.200.6:25,192.9.200.235:50815,>,250 2.1.5 Recipient OK,
    2018-03-06T19:06:39.383Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,14,192.9.200.6:25,192.9.200.235:50815,>,250 2.1.5 Recipient OK,
    2018-03-06T19:06:39.383Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,15,192.9.200.6:25,192.9.200.235:50815,>,354 Start mail input; end with <CRLF>.<CRLF>,
    2018-03-06T19:06:39.601Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,16,192.9.200.6:25,192.9.200.235:50815,*,,Proxy destination(s) obtained from OnProxyInboundMessage event. Correlation Id:c4200ec3-af02-4049-bf3c-3de1d5d7a23c
    2018-03-06T19:06:41.148Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,17,192.9.200.6:25,192.9.200.235:50815,>,"250 2.6.0 <2e52550a-364d-4e0c-b7e5-18d42b60a543@ICLEXC2.independentcement.com.au> [InternalId=10252086935561, Hostname=ICLEXC2.independentcement.com.au] 59120 bytes in 0.773, 74.671 KB/sec Queued mail for delivery",
    2018-03-06T19:06:41.148Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,18,192.9.200.6:25,192.9.200.235:50815,<,QUIT,
    2018-03-06T19:06:41.148Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,19,192.9.200.6:25,192.9.200.235:50815,>,221 2.0.0 Service closing transmission channel,
    2018-03-06T19:06:41.148Z,ICLEXC2\Anonymous Relay Connector ICLEXC2,08D53DBAFFEDF281,20,192.9.200.6:25,192.9.200.235:50815,-,,Local

    Wednesday, March 7, 2018 1:35 AM

All replies

  • Hello,

    Thanks for contacting our forum. Given the error message it seems an Exchange side issue, network related:

    Add the local server's IP to our hosts file: (for example)

    192.168.1.5 server

    192.168.1.5 server.domain.local

    Restart "Microsoft Frontend Transport" and "Microsoft Exchange Transport" services

    Hope it helps.


    Best Regards,
    Jason Chao


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.


    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    Thursday, March 8, 2018 2:52 AM
    Moderator
  • Hi Jason,

    Thanks for that.  We had already added the server's name and DNS name to the hosts file on itself as we had previously had the PRX5 error when trying to relay.  The host file solved that PRX5 error but we still occasionally get the intermittent error in the logs in the OP.

    Thursday, March 8, 2018 8:45 AM
  • Thanks for your respose. Sorry for later response cause i was in a vacation.

    Glad to hear the PRX5 issue has been resolved, you mean that it still existing the Socket errors.

    Firstly, please check if you have any message limitations on the relay receive connector;

    Do you have the same error on other connectors?

    Make sure the drive of the network card is the latest version.

    Hope it helps.


    Best Regards,
    Jason Chao


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.


    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    Thursday, March 15, 2018 3:17 AM
    Moderator