Hiding email address in O365 with hybird on-prem AD sync
So another gotcha when using O365 in hybird mode with on-prem sync is that you can’t hide a user’s email address [from address books and distribution lists] by using the Exhange Admin Portal. This is because the setting are made on-prem, and those defined values are simply pushing to your AAD tenant in Microsoft’s Azure cloud.
We used to be able to, from the Exchange Management Console on the on-prem server, just open the user and check a tick box to hide their address from everything. The work around isn’t much harder, it’s just buried deeper.
Open the user in your on-prem AD, and navigate the “Attribute Editor” tab.
Scroll down until you find the following attribute.
Setting it to “TRUE” will make the email addess hidden.
Setting it to “FALSE” or “<not set>” will make the email address visible.
After you have made the desired change to the value of the attribute, you just need to wait for [or force] your on-prem AD to re-sync with your AAD.