1. Locate user A’s distinguishedName
Get-User “User A” | Fl DistinguishedName
2. Launch ADSI Editor, go to “CN=Microsoft Exchange System Objects”, right-click the PF1 object, and then go to “Properties”
Notes: PF1 must be mail-enabled
3. In the “Attribute Editor” tab, locate “publicDelegates” attribute, and then copy user A’s DistinguishedName into it
from
https://social.technet.microsoft.com/Forums/office/en-US/d341ff3f-9a8c-40c7-ab04-0a1655047041/public-folder-not-accepting-ndr?forum=exchangesvrgenerallegacy