none
Mail between domain after O365 migration and dirsync

    Question

  • Hello,

    I have a multi domain exchange 2013. One of the domains was migrated to office 365 and mailboxes and domain was removed from the exchange.

    The synchronization is filtered down to the OU where the migrated users are. They only have proxy address and mail attribute. 

    Now users that are still on the on-prem exchange are unable to send mail to the domain that was migrated to Office 365 with the following error:

    Remote Server returned '420 4.2.0 Recipient deferred because there is no Mdb'

    I tried setting the migrated domain back into the exchange server as an external relay domain but that did not work. The on-prem exchange is still looking for the mailboxes in its DB. 

    The exchange is not in hybrid mode.

    Any ideas on how I can sidestep this?

    Thanks in advance,

    Haukur


    Tuesday, January 12, 2016 2:56 PM

Answers

  • Use targetaddress, not the primarySMTP. Or forwarding, or Transport rule, etc.
    • Marked as answer by Haukurso Thursday, January 14, 2016 10:23 AM
    Wednesday, January 13, 2016 2:07 PM

All replies

  • Change their targetaddresses to point to the user@tenant.onmicrosoft.com address. Or use any other way of forwarding.
    Tuesday, January 12, 2016 7:56 PM
  • Hello,

    I have a multi domain exchange 2013. One of the domains was migrated to office 365 and mailboxes and domain was removed from the exchange.

    The synchronization is filtered down to the OU where the migrated users are. They only have proxy address and mail attribute. 

    Now users that are still on the on-prem exchange are unable to send mail to the domain that was migrated to Office 365 with the following error:

    Remote Server returned '420 4.2.0 Recipient deferred because there is no Mdb'

    I tried setting the migrated domain back into the exchange server as an external relay domain but that did not work. The on-prem exchange is still looking for the mailboxes in its DB. 

    The exchange is not in hybrid mode.

    Any ideas on how I can sidestep this?

    Thanks in advance,

    Haukur


    Basically, once you migrate a mailbox to O365, the On Premises mailbox gets converted to a MEU with target address like alias@mail.tenant.onmicrosoft.com. So, make sure you have the MEU in place for the migrated mailboxes and with proper target address. Also, convert migrated domain to Internal Relay under Accepted Domain in local Exchange 2013.

    OM (MCITP) | Blog

    Tuesday, January 12, 2016 8:27 PM
  • Hi Haukur,

    After you migrate your one domain mailboxes to O365, what is the Primary SMTP configured there for them ?

    it should be username@yourdomain.onmicrosoft.com. while you sending an email to them from your on-Premises Exchange, are you using any contact object which is set to have a correct Target Address ?

    Please verify the above and also check the user object in local AD to ensure its attribute set correctly after migration.

    Also refer to https://community.office365.com/en-us/f/158/t/269324

    Thanks


    Mihir Nayak If a post is helpful, please take a second to hit the green arrow on the left, or mark as answer, thanks

    Wednesday, January 13, 2016 12:20 AM
  • Hi,

    Thank you all for the response. Problem is that the users are being synced to office 365 so attributes like proxyaddresses needs to match what the users settings for office 365. So if I change the primary SMTP value to user@tenant.onmicrosoft.com it will change the users primary address in office 365. That is not going to work for me. 

    Thanks

    Wednesday, January 13, 2016 1:28 PM
  • Use targetaddress, not the primarySMTP. Or forwarding, or Transport rule, etc.
    • Marked as answer by Haukurso Thursday, January 14, 2016 10:23 AM
    Wednesday, January 13, 2016 2:07 PM
  • Hi,

    According to your description, I want to confirm below points:
    1. Would you please post more details about your mail flow, MX record point to On-premise Exchange or Office online?
    2. How about send message from internet to Office Online?
    3. How about send message from Office Online to On-premise mailbox?
    4. How about send message from On-premise mailbox to new account in Office online?

    We need create connector to mail flow between On-premise and Exchange Online, for your reference: https://technet.microsoft.com/en-us/library/dn751020(v=exchg.150).aspx

    Once move mailbox from On-Premise to Office online, the user will be converted to a Remote Mailbox automatically in EMC, also as a mailbox-enabled user in Exchange Online.

    For your question, I suspect that the o365 account haven't enable remote mailboxes On-premise. Please try Enable-RemoteMailbox to create for testing.


    Please remember to mark the replies as answers if they help, and unmark the answers if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.

    Allen Wang
    TechNet Community Support

    Thursday, January 14, 2016 6:17 AM
    Moderator
  • Use targetaddress, not the primarySMTP. Or forwarding, or Transport rule, etc.

    Thank you Vasil, this is the solution I was looking for. 

    Thank you.

    Thursday, January 14, 2016 10:23 AM