These attributes are written back from Azure AD to on-premises Active Directory when you select to enable Exchange hybrid . Depending on your Exchange version, fewer attributes might be synchronized.
| Attribute Name | User | Contact | Group | Comment |
|---|---|---|---|---|
| msDS-ExternalDirectoryObjectID | X | Derived from cloudAnchor in Azure AD. This attribute is new in Exchange 2016. | ||
| msExchArchiveStatus | X | Online Archive: Enables customers to archive mail. | ||
| msExchBlockedSendersHash | X | Filtering: Writes back on-premises filtering and online safe and blocked sender data from clients. | ||
| msExchSafeRecipientsHash | X | Filtering: Writes back on-premises filtering and online safe and blocked sender data from clients. | ||
| msExchSafeSendersHash | X | Filtering: Writes back on-premises filtering and online safe and blocked sender data from clients. | ||
| msExchUCVoiceMailSettings | X | Enable Unified Messaging (UM) - Online voice mail: Used by Microsoft Lync Server integration to indicate to Lync Server on-premises that the user has voice mail in online services. | ||
| msExchUserHoldPolicies | X | Litigation Hold: Enables cloud services to determine which users are under Litigation Hold. | ||
| proxyAddresses | X | X | X | Only the x500 address from Exchange Online is inserted. |