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Cant send message '501 5.1.4 Recipient address reserved by RFC 2606' RRS feed

  • Question

  • Colleagues, good afternoon.

    There is a test domain named contoso. test. It has 4 EXCH servers deployed, 2 for 2013 and 2 for 2019. I moved several mailboxes from 2013 to 2019 server and noticed the following problem, when sending emails to new mailboxes, an error appears:
    test_admin (test_admin@contoso.test)
    There is a problem with the recipient's email system. More than one person has this email address. The recipient's system administrator will have to fix this problem.
    The following organization rejected your message: EXCH19-01.contso.test.

    Diagnostic information for administrators:
    Generating server: EXCH19-02.contoso.test
    test_admin@contoso.test
    EXCH19-01.contoso.test
    Remote Server returned '501 5.1.4 Recipient address reserved by RFC 2606'

    Sending from mailboxes in 2019 to 2013 passes correctly, 2013 to 2013 too. On the mailbox that was created immediately in 2019, the problem is the same as for those moved from 2013 to 2019. 

    Rejecteservedtoplevelrecipientdomains : False - the value is the same on all servers. In General, all settings of the *Reject* type are set to False. Anyway switch to True doesnt change anything. For 2013 clients too.

    Has anyone encountered this? In which direction to look for a solution?
    Saturday, October 31, 2020 8:38 PM

Answers

  • Well, looks like this domain blocked inside transport agent and not in receive connector.

    https://social.technet.microsoft.com/Forums/en-US/e0fe3974-26f0-4fcb-bb2d-853e45b48811/setreceiveconnector-rejectreservedsecondlevelrecipientdomains-has-no-effect-on-rfc-2606-rejection?forum=Exch2016GD

    I cant understand that logic. We have settings which we can change on receive connector - RejectReserved*LevelRecipientDomains, but there is no point. 

    • Marked as answer by Валера2 Monday, November 2, 2020 6:36 AM
    Sunday, November 1, 2020 7:09 PM

All replies

  • Hi,

    The Exchange Server (non-development) forum has been migrated to the new Microsoft Q&A platform, I suggest asking over here:
    https://docs.microsoft.com/en-us/answers/topics/office-exchange-server-administration.html

    (Please don't forget to mark helpful replies as answer, thank you)

    Best regards,
    Leon


    Blog: https://thesystemcenterblog.com LinkedIn:

    Sunday, November 1, 2020 7:57 AM
  • https://social.technet.microsoft.com/Forums/windows/en-US/5f9b814c-ada7-41a3-9f7b-755a9e058377/exchange-2016-failed-to-deliver-mail-after-a-new-installation?forum=Exch2016MFSM

    please check hope it will help you

    Sunday, November 1, 2020 8:33 AM
  • Well, looks like this domain blocked inside transport agent and not in receive connector.

    https://social.technet.microsoft.com/Forums/en-US/e0fe3974-26f0-4fcb-bb2d-853e45b48811/setreceiveconnector-rejectreservedsecondlevelrecipientdomains-has-no-effect-on-rfc-2606-rejection?forum=Exch2016GD

    I cant understand that logic. We have settings which we can change on receive connector - RejectReserved*LevelRecipientDomains, but there is no point. 

    • Marked as answer by Валера2 Monday, November 2, 2020 6:36 AM
    Sunday, November 1, 2020 7:09 PM
  • hi

    https://stackoverflow.com/questions/39118128/php-mailer-to-outlook-data-not-accepted-recipient-address-reserved-by-rfc-2606

    Sunday, November 1, 2020 8:46 PM
  • It works only with code. If you need to test the work of mailboxes in exchange, you will have to recreate the domain.
    Monday, November 2, 2020 6:36 AM
  • Hi Валера2,

    Exchange Development forum isn't supported by Microsoft. Exchange Forum has been migrated to a new home on Microsoft Q&A

    If you have more questions about Exchange server, welcome to post them in that new forum. If you have question about script or EWS development, you can keep post in current Forum.

    About this question, you can check whether is this email blocked by "Intra-Organization" connector. This connector is an implicit connector which will not effect by any modify. So, email is still blocked after modifying.

    Regards

    Kyle Xu

    Monday, November 2, 2020 7:58 AM