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Slow Email Delivery (both internal and External) Exchange 2016 on-premise RRS feed

  • Question

  • Hi,

    We have an on-premise Exchange 2016 Servers. Just recently we've had a user complain that SOME emails (a mixture of internal and external) are taking a long time to arrive. 

    i.e an internal email sent @ 12:21am was received @  12:36am, another  was sent at 6:32am and received at 6:41am and another was sent at 6:34am and received at 6:41am.

    Here are the HEADERS of one email

    Received: from XXXXXXXEX01.XXXXXXX.XXX (XXX.XXX.XXX.XXX) by

     XXXXXXXEX01.XXXXXXX.XXX (XXX.XXX.XXX.XXX)with Microsoft SMTP Server

     (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5

     via Mailbox Transport; Wed, 19 Jun 2019 06:41:21 +1000

    Received: from XXXXXXXEX01.XXXXXXX.XXX (XXX.XXX.XXX.XXX)by

     XXXXXXXEX01.XXXXXXX.XXX (XXX.XXX.XXX.XXX)with Microsoft SMTP Server

     (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id

     15.1.1713.5; Wed, 19 Jun 2019 06:34:06 +1000

    Received: from XXXXXXXEX01.XXXXXXX.XXX (XXX.XXX.XXX.XXX)  ([XXXX::XXXX:XXXX:XXXX:XXXX]) by

     XXXXXXXEX01.XXXXXXX.XXX (XXX.XXX.XXX.XXX)  ([XXXX::XXXX:XXXX:XXXX:XXXX]) with mapi id

     15.01.1713.004; Wed, 19 Jun 2019 06:34:06 +1000

    Content-Type: application/ms-tnef; name="winmail.dat"

    Content-Transfer-Encoding: binary

    Any help or advise would be appreciated. 

    Thanks


    Friday, June 21, 2019 12:36 AM

All replies

  • Hi TheWanKing,

    Did you change anything on the server recently ? Is there only one user have the delay issue ?

    You can try to check the message tracking log on these specific delayed messages , that would show us the details about where and when the message delay:

    Search message tracking logs

    Moreover, you can also try using message analyzer in EXRCA to help analyze the message header, this tool will analyze the email’s path and, based on the timestamps when it passed the different machines, it will tell you the exact source that is responsible for delaying the message delivery.



    Best Regards,
    Niko Cheng


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    Friday, June 21, 2019 6:01 AM
    Moderator
  • Hi,

    Havent made any changes. In this case we've had a different user with the same issue. This is what i got from the Exchange Delivery REport. As you can see there's a 14 minute delay

    We noticed the time it happened mail was queuing on this server

    Delivery Report for  USERXXXXX ‎(USERXXXX@COMPANYXXXXXX.com)‎

    Pending
    1/07/2019 12:22 PM serverex01.internalname.com
    Message was received by serverex01.internalname.com from serverex02.internalname.com.

    1/07/2019 12:36 PM serverex01.internalname.com
    The message has been transferred from serverex01.internalname.com to serverex01.internalname.com.
    Delivered
    1/07/2019 12:36 PM serverex01.internalname.com
    The message was successfully delivered.


    • Edited by TheWanKing Monday, July 1, 2019 3:03 AM
    Monday, July 1, 2019 3:00 AM
  • Delving deeper into the Rabbit Hole we discovered HADISCARD message for the above log. We changed the -MaxInboundConnectionPerSorce for each connector on this server from the default of 20 to 200. Will monitor to see how it goes. 
    Monday, July 1, 2019 3:18 AM
  • Hi TheWanKing,

    How about the result after changing the MaxInboundConnectionPerSource value?  If you have any questions or needed further help on this issue, please feel free to post back. If the issue has been resolved, please mark the helpful replies as answers, this will make answer searching in the forum easier and be beneficial to other community members as well.

    Thanks for your understanding.

    Best Regards,
    Niko Cheng


    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.


    Wednesday, July 3, 2019 9:38 AM
    Moderator