Unable to Send mail to another domain RRS feed

  • Question

  • Hi,

    I currently have an issue with sending emails to a user on a specific domain. I have 3 Exchange 2013 CU16 servers in a DAG.

    The issue is I'm trying send an email to user from the following user, I keep getting the below error:

    Remote Server returned '550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found'<o:p></o:p>

    The doesn't exist on the exchange environment at The user has never been created.

    I'm not really sure on why its referencing the user at

    What could potentially cause this issue?

    Thursday, January 18, 2018 7:33 AM

All replies

  • Are you replying to an e-mail or addressing it from your autocomplete cache or using an Outlook Contact?  If so, try entering the SMTP address directly.  If you can track that the message is actually being sent to the other organization, then it's their problem and not yours.

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

    Thursday, January 18, 2018 9:53 PM
  • Hi

    It looks like there was a contact object for user and that contact object was deleted.

    If user used this contact to send emails to it, the address is cached in his Outlook address cache.

    When the contact is deleted and tries to send an email to, outlook automatically propose this cached address. By sending the email exchange tries to deliver the mail to the Exchange internal address or legacyExchangeDN. Because the contact doesn't exist anymore you get this typical error message IMCEAEX....

    User can resolve it by deleting the address from his outlook address cache, or you create a contact object for and additionally add the X500 address to the contact according to the error message: X500:/o=site_xyz/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=7d77498327794679a71d096418426607-Lee user1

    Hope that helps.


    Pano Boschung, PageUp AG

    Thursday, January 18, 2018 10:04 PM
  • Hi,

    Thanks for all the replys.

    I've removed all the cache addresses from Outlook 2016 via "Empty Auto-Complete List"

    Their doesn't seem to be a contact in Exchange at all for this user in Also the user is only in

    Friday, January 19, 2018 2:44 AM
  • Hi Maksoy,

    As Ed mentioned, if you entry the SMTP address ( directly, does the same issue occur?

    You can also try using OWA to send the email and check if the same issue persists.

    Best Regards,

    Niko Cheng

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

    Friday, January 19, 2018 8:44 AM
  • Hi Mak,

    Could you also check user has local contact created on their mailbox for Also share Non delivery mail for finding out the origin.

    Regards, Krselva. Please remember to mark the replies as answers if its helps you, and unmark the answers if it is not help you.

    Friday, January 19, 2018 10:25 AM
  • Hi,

    Sorry about the late reply. We are still working on this issue. Yes if you type in the smtp address directly it still occurs.

    Also their is no local contact in outlook for this email.

    Monday, January 29, 2018 1:10 AM
  • Hi Maksoy,

    How about the result using OWA to send ?

    Best Regards,
    Niko Cheng

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

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    Thursday, February 1, 2018 9:07 AM