Hi All, I have so many external contacts in our Exchange 2010 environment. Currently those contacts are randomly located on many DL too, I want to prevent the owner DL so he/she cannot modify member for external contacts only, can Exchange do that ?Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Krisna Ismayanto | My blogs: Krisna Ismayanto | Twitter: @ikrisna

If you want to stop a owner of group from adding existing contacts to a group, then no, that cannot be done. Any mail enabled object can be added to the group membership. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.

If you want to stop a owner of group from adding existing contacts to a group, then no, that cannot be done. Any mail enabled object can be added to the group membership. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.

You could hide that external contacts from GAL if you dont use those contacts to send emails directly.

Yes, it seems that you cannot do that by Exchange. Frankly speaking, it is the owner's responsibility to manage his group. Restricting it by your company's policy is more effective. Frank Wang TechNet Community Support

Yes, it seems that you cannot do that by Exchange. Frankly speaking, it is the owner's responsibility to manage his group. Restricting it by your company's policy is more effective. Frank Wang TechNet Community Support

Hi Krisna, Any updates?Frank Wang TechNet Community Support

Hi Krisna, Any updates? Frank Wang TechNet Community Support Hi Frank, nope, already inform the user that Exchange cannot do that.Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Krisna Ismayanto | My blogs: Krisna Ismayanto | Twitter: @ikrisna