From: chriske911 on
using outlook 2007 with an xc 2007 SP1 server I have the following
issue when adding sharing permissions on a public folder

when I select a certain distribution group to have whatever permission
on a public folder (of the contacts type) I get an error:

"one or more users cannot be added to the folder access list. Non-local
users cannot be given the rights on this server."

all users in this group have a normal user mailbox (non-shared) and I
already changed the used distribution group into an universal securtiy

but to no avail

what else can I try