Forum Discussion
Luke_IT
Jun 13, 2023Copper Contributor
LegacyDN with EXO (Microsoft 365)
Hi all, suddenly out of nowhere one of the Outlook clients in an office is unable to send an email to a M365 native recipient of the same org which never was migrated from onprem Exchange as this ...
mderooij
Jun 13, 2023MVP
IMO, this warrants a support call as the legacyExchangeDN should not change. Unless something happened on the back-end. Make sure there is no IAM process that recreated the user/mailbox or another process that overwritten it; a (proper) restore w/reconnect (to mailbox) should not be a problem. And yes, behind the scenes, legacyExchangeDN is still used for internal resolution of recipients.