New distribution list cannot recieve external emails

Leon Moore 1 Reputation point
2022-10-19T03:28:15.077+00:00

Hi there,

I created a distribution list yesterday - when external senders try to send email to it they receive a "Email not delivered - couldn't find address at domain"
I've done a forced sync, I've ensure the receive external email settings are switched on, nothing changes. All my other distribution lists work fine and are set up in precisely the same way.

Is there anything I can do or is this list forever going to be broken?

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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  1. T. Kujala 8,706 Reputation points
    2022-10-19T03:43:15.603+00:00

    Hi @Leon Moore ,

    "Delivery has failed to these recipients or groups - the address you sent your message to wasn't found at the destination domain"

    Have you tried to add an another SMTP address?

    Does it work then?


  2. Vasil Michev 98,196 Reputation points MVP
    2022-10-19T07:25:55.067+00:00

    Can you post the exact NDR message? If it's "550 5.4.1 Recipient address rejected: Access denied", the most likely issue here is Directory-based Edge Blocking not reflecting the new address. For some cases, you might actually need to disable DBEB: https://learn.microsoft.com/en-us/exchange/mail-flow-best-practices/use-directory-based-edge-blocking#configure-dbeb


  3. KyleXu-MSFT 26,226 Reputation points
    2022-10-20T02:01:54.36+00:00

    @Leon Moore

    I've done a forced sync,

    Did you create group object on the local AD then sync to Azure AD? If so, I would suggest remove this one, then create a distribution group from Exchange online directly. After creating group on Exchange online, make sure the Delivery Managment is enabled as below for this group:
    252176-1.png

    It could help us quick narrow down whether this issue caused by the object that you create on local AD.


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