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nyquist340's avatar
nyquist340
Copper Contributor
Jul 09, 2020

IMCEAEX NDRs 50% solved - Exchange 2013

Hello,

 

After DB corruption and re-creating two mailbox accounts, adding new X500 email address entries (based on email NDRs "mailto:" fields) and deleting cached contact information in outlook clients, I've ended up with a functional account  and  the other account (let's say ABC@smooth.com) not being able to receive emails.

The weird thing is, outlook clients are caching the contact with a typo from somewere I'm not being able to find nor fix. Even weirder, users are able to send emails for a first time if they delete cached contact information and then type the email address manually, but on a second attempt they receive a NDR message with the wrong X500 email address.

Exchange side X500 entry:
/o=corp123/ou=Exchange Administrative Group (FYDIBOHF4141415)/cn=Recipients /cn=ABC@smooth.com

 

Outlook NDR:

/o=corp123/ou=Exchange Administrative Group (FYDIBOHF4141415)/cn=Recipients /cn=ABzC@smooth.com

 

I've restarted several services and tried restarting the server. No luck.

 

Did I missed something when re-creating the mailboxes in the Exchange Server?

 

Thanks in advance!
Max

 

Exchange 2013
IMCEAEX
NDR
  • marguelles's avatar
    marguelles
    Copper Contributor
    Jul 11, 2020

    Based on many posts I've been reading, I modified the X500 entry by removing the "@smooth.com".

     

    Before
    /o=corp123/ou=Exchange Administrative Group (FYDIBOHF4141415)/cn=Recipients /cn=ABC@smooth.com

    After
    /o=corp123/ou=Exchange Administrative Group (FYDIBOHF4141415)/cn=Recipients /cn=ABC

     

     

    Now the NDR emails shows the following 😞
    /o=corp123/ou=Exchange Administrative Group (FYDIBOHF4141415)/cn=Recipients /cn=ABzC

     

    User's DN appears to be OK within AD.

    Any ideas?

    Max

    • JeremyTBradshaw's avatar
      JeremyTBradshaw
      Steel Contributor
      Jul 12, 2020
      marguelles, have you seen this kb?
      https://support.microsoft.com/en-ca/help/4039597/ndr-when-delegate-sends-update-to-meeting-in-o365-hybrid

      It might not be your exact scenario, but just imagine the big underlying theme is having some but not all recipients present in the local Exchange org where the ndr is being generated.

      In my experience, Exchange servers add the @domain onto the end of the legacyExchangeDN / x500 when they can't find that recipient in the local directory. But the @domain only shows in the ndr, not on the actual ldn/x500 being searched for.

      Not sure if this will help but figured I'd throw it out there just in case.
      • marguelles's avatar
        marguelles
        Copper Contributor
        Jul 21, 2020

        Hi JeremyTBradshaw,

         

        Apparently, the issue got resolved by removing the @domain.inc from the X500 entry!

        Thanks for your answer!

        Regards,

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