none
Odd Problem With Lost Messages

    Question

  • I've had a few people report that they send messages using our Exchange server and the recipient never receives it.  Here's what I know:

    - The message does appear in the "Sent Items" folder of the sender, so they're not stuck in the Outbox.

    - The message is not found in the Message Journal.

    - The message is no where to be found in searches of the Delivery Reports using the EAC.

    - The message can either be on our Exchange server (completely internal), between us and a sister Exchange server (different forest) or sent to an SMTP address outside of our company.

    - Not all messages fail--only some of them.

    - The failures seem to come in batches instead of a random single message here and there.  It's more like 7 messages in a row are lost and then it starts working again.

    We're a single server Exchange 2013 environment (CU3).  Yes, we're behind on patches.  Next maintenance window...

    Does this sound at all familiar?  If this is a known bug, I want to be sure it's fixed in the CU level that I move to.

    Thanks!

    Patrick

    Thursday, June 30, 2016 3:57 PM

Answers

  • I would wait to see if installing the latest Exchange CU fixes the issue.  Also make sure your Outlook client are up to date on patches as well. 

    If it doesn't work after the updates, you could check the log files on the CAS server around the time of the message in the sent folder and see if there were any client related errors.

    Check: "\Program Files\Microsoft\Exchange Server\V15\Logging\HttpProxy\Ews"

    Also you could enable global logging on the Outlook client and see if you find any connection related errors there:

    https://support.microsoft.com/en-us/kb/2862843

    Thursday, June 30, 2016 8:28 PM

All replies

  • Are these POP, IMAP or Exchange Clients?
    Thursday, June 30, 2016 4:08 PM
  • All Exchange clients.  Outlook for Windows, Outlook for Mac, iPhone via ActiveSync.
    Thursday, June 30, 2016 6:38 PM
  • I would wait to see if installing the latest Exchange CU fixes the issue.  Also make sure your Outlook client are up to date on patches as well. 

    If it doesn't work after the updates, you could check the log files on the CAS server around the time of the message in the sent folder and see if there were any client related errors.

    Check: "\Program Files\Microsoft\Exchange Server\V15\Logging\HttpProxy\Ews"

    Also you could enable global logging on the Outlook client and see if you find any connection related errors there:

    https://support.microsoft.com/en-us/kb/2862843

    Thursday, June 30, 2016 8:28 PM
  • Good ideas.  

    I'm still thinking through the behavior, though.  How does a message get into the "Sent Items" folder for a mailbox without actually being sent?  There was no tracking information in the Delivery Reports on the server.  I'm trying to imagine how that happens...

    Thursday, June 30, 2016 9:16 PM
  • Client Connectivity issues would cause that behavior like spotty wifi or other network issues between the client and CAS server. If you're using a load balancer or have a firewall between the clients and CAS server, check the logs there as well. You also could be hitting client throttling limits which would disconnect the email client from the server. Check the application logs on the CAS server to look for this. Checking the client logs on the CAS server and matching up with the time stamp on the unsent messages might uncover this as well.
    Friday, July 1, 2016 12:30 AM
  • Hi,

    First follow above suggestion to upgrade the latest Exchange CU.

    Try to use the following command to track the missing message:

    Get-Messagetrackinglog -sender user@cu1.com -MessageSubject "Email Subject"|fl

    Also check if you can find the emails are stuck in the queue viewer.

    https://technet.microsoft.com/en-us/library/bb123934(v=exchg.160).aspx

    Regards,

    David



    Please remember to mark the replies as answers if they help, and unmark the answers if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.

    David Wang_
    TechNet Community Support

    Friday, July 1, 2016 2:41 AM
    Moderator