Hi @Diane PALISCAK ,
What is the version of your Exchange server?
I have never got this error for Exchange 2013 and Exchange 2016 or upper versions.
I found an method about clearing the legacyExchangeDN, check the follow steps and see if these could help:
Using ADSIEdit, connect to the Configuration naming content.
Navigate to the Servers container.CN=Services
CN=Microsoft Exchange
CN=OrganizationName
CN=Administrative Groups
CN=Exchange Administrative Group (GUID)
CN=Servers
Right click on the relevant Exchange Server (e.g. CN=Ex1) and edit the properties.Find the legacyExchangeDN attribute, replace the value with your server name such as Ex1.
Best regards,
Lou
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