Symptoms
The LegacyExchangeDN value doesn’t clear for some users when they run the Disable-RemoteMailbox command in on-premises Microsoft Exchange Server 2019. The LegacyExchangeDN attribute identifies whether a mailbox is still active. This issue creates inconsistencies in the internal environment.
Resolution
To fix this issue, install Cumulative Update 12 for Exchange Server 2019 or a later cumulative update for Exchange Server 2019.
