Does changing the email field on the on-prem field cause Legacy DN Value?

muhi-entra 0 Reputation points
2024-01-30T16:46:09.7966667+00:00

Hello, We have a hybrid environment with on-premises AD syncing to their Azure AD We converted an on-prem user profile to External ID in Azure AD. As a result, sending party is receiving an NDR whenever they try to send an e-mail to this converted user. We later found out that the legacy DN value somehow changed during the conversion process, hence the reason the sending party receives a bounce back when they select the converted user from their outlook cached profile. Part of the procedure when we converted the user to External ID, we turned of Sync, changed the email field to match the external email address and then turned on Sync.

My question is: Does updating he email field cause the legacy DN value to change?
Does toggling the Sync option cause the legacy DN value to change?

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  1. Akhilesh 6,825 Reputation points Microsoft Vendor
    2024-01-31T09:56:39.26+00:00

    Hi @muhi-entra

    Thank you for post!

    The email field is a different attribute that can be modified without affecting the legacy DN value, so updating the email field does not cause the legacy DN value to change.

    The Sync option allows the on-premises Active Directory objects to match the Entra ID Directory Objects Sync option and the legacy DN value are independent of each other and do not affect each other so toggling the Sync option does not effect the legacy DN value to change.

    The other side receiving an NDR when sending an email to user could you please share the NDR message for the error code and the reason for the failure. Also let us know is the legacy DN value is change manually?

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  2. Andy David - MVP 144.2K Reputation points MVP
    2024-01-31T13:00:44.3533333+00:00

    Throughout the years whenever you "convert" a mail-enabled object, it creates a new legacyExchangeDN for that object.