We use on-prem Active Directory which is synced to Office365.
Today I notice that we have "DirSync Errors" and in investigating I've found that for a particular Mail Contact there are 2 objects in Office365, but only 1 on-prem, all with the same SMTP addresses.
When trying to Remove-MailContact with the not wanted object in Office365, I'm told I have to do it on-prem. On-prem doesn't have the duplicate, only the original. I've tried deleting the original mail contact on-prem, and it does remove it from Office365, but the "extra" mail contact still appears in Office365, which I still can't delete.
How can I delete the "extra" Mail Contact in Office365?