Staged migration to O365, NDR from non-migrated to migrated users

Posted on 2014-08-29
Last Modified: 2014-09-02

I am in the middle of a staged migration from our On Premise Exchange 2010 to Exchange Online. Everything is smooth so far and I successfully started migrating some internal users. However, non migrated users receive an NDR when trying to reach newly migrated users. I found the culprit, which is the autocomplete. Typing the complete address or deleting the autocomplete entry resolve my issue.  Is there is any way to force the update dynamically those entries ?

Thanks !
Question by:maxalarie
    LVL 37

    Accepted Solution


    How did you do the migration? The issue you are running into is related to the legacyExchangeDN value (see my article here - Depending on the method and tools you are using to migrate, the legacyExchangeDN may not have been migrated over as an X500 address. To resolve this, you will need to export all the legacyExchangeDN values from your on-premise mailboxes and import them into the O365 mailboxes as X500 addresses.

    LVL 2

    Author Closing Comment

    Hi Jamie,

    Thanks for your help, You are right, the LegacyExchangeDN have not been migrated as an X500 address. After resolving this, mails are not bouncing back anymore.

    Featured Post

    How your wiki can always stay up-to-date

    Quip doubles as a “living” wiki and a project management tool that evolves with your organization. As you finish projects in Quip, the work remains, easily accessible to all team members, new and old.
    - Increase transparency
    - Onboard new hires faster
    - Access from mobile/offline

    Join & Write a Comment

    Suggested Solutions

    Sometimes Outlook might have problems sending a message. There may be various causes- corrupted PST, AV scanner etc. The message, instead of going to the Sent Items folder, sits in the Outbox indefinitely. To remove it you can use a free tool cal…
    ADCs have gained traction within the last decade, largely due to increased demand for legacy load balancing appliances to handle more advanced application delivery requirements and improve application performance.
    In this video we show how to create an Address List in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: First we need to log into the Exchange Admin Center. Navigate to the Organization >> Ad…
    In this Micro Video tutorial you will learn the basics about Database Availability Groups and How to configure one using a live Exchange Server Environment. The video tutorial explains the basics of the Exchange server Database Availability grou…

    734 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    25 Experts available now in Live!

    Get 1:1 Help Now