exchange ndr

eg1995 1,126 Reputation points


i am experiencing this error with a newly created user:
Generating server:
IMCEAEX-_o=Be+20Bank_ou=Exchange+20Administrative+20Group+20+28FYDIBOHF23SPDLT+29_cn=Recipients_cn=dc4ccc17a1604f8a97cb21c04fd622a9-Dona+20ea@keyman .com
Remote Server returned '550 5.1.11 RESOLVER.ADR.ExRecipNotFound; Recipient not found by Exchange Legacy encapsulated email address lookup'

can you please advise

thank you

Exchange Server Management
Exchange Server Management
Exchange Server: A family of Microsoft client/server messaging and collaboration software.Management: The act or process of organizing, handling, directing or controlling something.
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Accepted answer
  1. Lucas Liu-MSFT 6,156 Reputation points

    Hi @eg1995 ,

    1. If you send email in outlook, when the Autocomplete feature tries to input the recipient name or address for you, manually click the "X" to delete the entry, and then manually type the whole email address again.
    2. You also could add a X.500 email address for user. Please follow the steps:
    1. You could follow the method in the second link provide by AshokM-8240 to get the actual X.500 address.
    2. Open the EAC and select the user mailbox which email address has issue.
    3. Click the edit , then you could add X.500 email address on the email address page.
    4. Then try to send an email again and see if the issue is resolved.


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  1. Ashok M 6,496 Reputation points


    Please try to send email from OWA and check if its working fine. If it works, then the issue is with the outlook cache, refer the below article

    If it happens in any client, then check the legacyexchangeDN and update the same,

    Please Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.

    If the above suggestion helps, click on "Accept Answer" and upvote it.