Just a reminder. If you are in hybrid mode and using public folders on-premises, the mail-enabled PFs will *not* be visible via the Outlook Address Book for 365 mailboxes – even if they are not hidden from the GAL. All you will see is:
This also means the display name will not be resolvable when creating or receiving a message from the folder.
One work-around is described here under the section “Configure Directory Synchronization” that allows you to create mail-enabled contacts in 365 that represent the PFs.
In the meantime, you will have to wait for one of two solutions:
- True mail-enabled PF synchronization.
- Supported Modern Public Folder Migration to Office 365. ( Yea, that’s right – The migration of 2013/2016 Public Folders to Office 365 is not supported right now.