Just want to share the issue we had with distribution list during the migration to Exchange 2010 from Exchange 2007.
Some Owners were not able to modify the members thru outlook.
The reason was different from RBAC that everybody was facing on the Internet which is explained below
In our case reason was that DL were non-universal as soon as we changed the DL's to Universal , our issue got fixed.
It was a short experience that I want to share with you all.