No errors are produced. Only the outcome of the user accounts that have an unregistered domain get disabled, if used in conjunction with the Arctera Unified Platform Exchange Online Sync.
During an Exchange Online Sync run, all domains belonging to a customer M365 tenant are first fetched and then validated to determine if they are registered. If there are any unregistered domains in M365 then those accounts in Arctera Unified Platform will get disabled after that sync completes. This behavior is by design.
This is commonly seen with users that do archiving as the email addresses have an unregistered domain.
This behavior is as designed.
Please create a Support case if there is a need to create an exception for the unregistered domain so it can be used simultaneously with the Arctera Unified Platform Exchange Online Sync.
User accounts with an unregistered domain get disabled after each Exchange Online Sync run in Arctera Unified Platform
JIRA: EVC-12843 JIRA: CFT-4280