I have AD users that are non-employees but in our domain to use our SharePoint 2013 on-prem instance. At the same time they are also a mail contact as they need to be in distribution groups. We use Office 365 for Exchange Online and azure ad connect to sync our users from AD to Office 365.
Since this user has an email address in their profile and the same email for their mail contact I am getting an Identity synchronization Error Report for this selected user. In the error description it notes the the user's ProxyAddress duplicated in active direct (mail contact). But we actually need to the duplicates to exist.
Wondering if anyone has run into this issue and best way around the issue?