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Mail won't deliver on email with new domain with error "message header size exceeds limit" RRS feed

  • Question

  • Exchange 2016 on-premise

    Hi everyone,

    We bought a new domain for our company. 
    We wanted to add this new domain to our Exchange server.

    First, we configured an MX record to point on our managed ironport (online), added the new domain to the RAT and we then added this domain to the "Accepted domains" list in Exchange.

    When I try to send an email externally, an error is returned to the sender :
    "The following message to <xxx@xxx> was undeliverable.
    The reason for the problem:
    5.3.0 - Other mail system problem 552-'#5.3.4 message header size exceeds limit'"
    If I send the email on one of our other domain already configured in exhange, the mail is delivered.

    Internally, the mail are delivered just fine on the new domain (and the old ones).

    When I check our IronPort, we can see the email being sent to our Exchange server but I can't see the mail on our Exchange log or Message Tracking and the email is not delivered.

    Our header size limit in Exchange is 256kb.

    Did we forget something ?
    We can't find what we missed !

    Thanks in advance.

    Kind regards,

    Leo
    Thursday, May 2, 2019 9:59 AM

Answers

  • Fond the solution, my fault, I should have asked our contractor to check again the IronPort configuration.

    They forgot to add the SMTP routes of our new domain...

    It might help someone in the future so I'll leave this here.

    Thanks for your help anyways !

    Leo


    • Edited by High-Tea Friday, May 3, 2019 3:18 PM
    • Marked as answer by High-Tea Friday, May 3, 2019 3:18 PM
    Friday, May 3, 2019 3:17 PM

All replies

  • Hi,

    What is the "generating server" on this NDR message? Is it your Exchange server or sender‘s server?

    If the generating server is your Exchange server, it means this email is blocked by Exchange server, I would suggest you check all connector in your organization with command below:

    Get-ReceiveConnector -Server exch2016 | fl name,MaxHeaderSize

    Then try to send a blank email to check whether is it will be blocked.

    If the generation server isn't your Exchange server, it means this email isn't blocked by your Exchange server.

    Regards,

    Kyle Xu


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    Friday, May 3, 2019 5:41 AM
  • Hello,

    Thank you for your answer.

    It looks like it is our Exchange server that is sending the error because we can see in our IronPort that the mail is accepted but, it says "bounced by destination server":

    - "(DCID 896440) Message 1032152 to xxx@xx.xx bounced by destination server. Reason: 5.3.0 - Other mail system problem ('552', ['#5.3.4 message header size exceeds limit'])"

    After a few tries, we get this error on the ironport :

    - "Message 1032153 aborted: Receiving aborted"

    In Exchange, all of our connector have a max header size of 256 KB (which should be enough I think, I tried again with a blank email) :

    "Name          : XXX
    MaxHeaderSize : 256 KB (262,144 bytes)

    Name          : XXX
    MaxHeaderSize : 256 KB (262,144 bytes)

    Name          : XXX
    MaxHeaderSize : 256 KB (262,144 bytes)

    Name          : XXX
    MaxHeaderSize : 256 KB (262,144 bytes)

    Name          : XXX
    MaxHeaderSize : 256 KB (262,144 bytes)

    Name          : XXX
    MaxHeaderSize : 256 KB (262,144 bytes)

    Name          : XXX
    MaxHeaderSize : 256 KB (262,144 bytes)"

    Kind regards,

    Leo

    Friday, May 3, 2019 11:45 AM
  • Fond the solution, my fault, I should have asked our contractor to check again the IronPort configuration.

    They forgot to add the SMTP routes of our new domain...

    It might help someone in the future so I'll leave this here.

    Thanks for your help anyways !

    Leo


    • Edited by High-Tea Friday, May 3, 2019 3:18 PM
    • Marked as answer by High-Tea Friday, May 3, 2019 3:18 PM
    Friday, May 3, 2019 3:17 PM
  • I am happy to see that your problem has been solved. This suggestion will be useful to other people narrow down the similar issue.

    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.

    Monday, May 6, 2019 7:07 AM