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cant receive external mail

    Question

  • i have copied a working account in ad and created a mail box for it.

    send and receive in internal is ok, but receive from external gives a bounce back message to the sender.

    what may be the cause?

    bounce back message:

    550 5.1.1 User unknown


    • Edited by daniel gor Wednesday, April 18, 2018 6:36 AM
    Wednesday, April 18, 2018 4:10 AM

All replies

  • Hi Daniel,

    Can you open exchange management shell and post the output of the command:

    get-mailbox -identity "user@company.com"


    Regards

    Simon


    If you find that my post has answered your question, please mark it as the answer. If you find my post to be helpful in anyway, please click vote as helpful. Regards Simon Disclaimer: This posting is provided AS IS with no warranties or guarantees, and confers no rights.

    Wednesday, April 18, 2018 1:48 PM
  • Hi daniel gor,

    Things we want to confirm with you: 
    1. How many people cannot receive mails from internet?
    2. Do you have a MX record?

    If all users cannot receive mails from internet, please make sure you have create a MX record points to your Exchange server and open the 25 port on your server.

    If only some of users cannot receive mails from internet, please use the command below to check the value of RequireSenderAuthenticationEnabled about this mailbox. Make sure this value is false.
    Get-Mailbox user@contoso.com| fl *RequireSende*

    Regards,

    Kyle Xu


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.

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    Friday, April 20, 2018 1:44 AM
    Moderator
  • Hi daniel gor,

    Any update now?
    If the above suggestion helps, please be free to mark it as answer for helping more people.

    Regards,

    Kyle Xu


    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.

    Sunday, April 22, 2018 1:50 PM
    Moderator