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DNS records for this domain are configured in a loop

    Question

  • Hello,

    On-premise Exchange 2013   : User A
    Office 365                                 : User B

    User B is able to email User A fine.
    User B can email anyone else (on-premise or office 365 or external)
    User A can email anyone else (On-premise or external or Office 365, other than UserA)

    Everyone else can email each other or external and receive emails fine.

    User A to User B causes the error:

    Remote Server returned '< #5.4.4 smtp;554 5.4.4 SMTPSEND.DNS.MxLoopback; DNS records for this domain are configured in a loop>'

    Message trace on Exchange 2013 shows the message being Submitted but nothing beyond that. MessageTrackingLog shows the below error as well.

    RecipientStatus         : {[{LRT=};{LED=554 5.4.4 SMTPSEND.DNS.MxLoopback; DNS records for this domain are configured in a loop};{FQDN=};{IP=}]}

    All mails are delivered to on-premise, ie. MX is pointed to on-premise. I have recreated UserA's mailbox but no change. Still happens. 

    Any suggestions?

    Regards,
    Ramu V Ramanan

    Monday, August 1, 2016 5:49 AM

Answers

  • What on-premises recipient objects are configured with an e-mail address for User B?

    What Office 365 recipient objects are configured with an e-mail address for User B?

    Have you tried clearing the nickname cache for user A, or directly addressing User B from the address book?


    Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."
    Celebrating 20 years of providing Exchange peer support!



    Monday, August 1, 2016 6:12 PM
    Moderator

All replies

  • What on-premises recipient objects are configured with an e-mail address for User B?

    What Office 365 recipient objects are configured with an e-mail address for User B?

    Have you tried clearing the nickname cache for user A, or directly addressing User B from the address book?


    Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."
    Celebrating 20 years of providing Exchange peer support!



    Monday, August 1, 2016 6:12 PM
    Moderator
  • Thanks Ed, the RecepintType on User B was the issue, but it would not work on the original User B. 

    I had to remove and recreate the user in AD, Sync to Office 365, Assign License, wait for mailbox to be created online and and then use the Shell to set the RecepientType in UserB to get it to be able to work fine.

    Not sure what was wrong, and why the recepienttype would not get recreated correctly, but it had the correct recepienttype domains setup earlier automatically. Its only a single user who was affected, so I am happy to fix it with the shell.

    Thanks for pointing in the right direction.

    Regards,

    Ramu


    Ramu V Ramanan

    Monday, August 1, 2016 11:52 PM
  • You're welcome.  Happy to have helped.

    Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."
    Celebrating 20 years of providing Exchange peer support!

    Tuesday, August 2, 2016 3:32 AM
    Moderator