After migrating to Exchange 2010 users are not able to modify the non-universal distribution groups using outlook. However they are able to modify all the distribution groups using ECP. Can anyone explain me the technical reason?

Because they're not universal.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

Not really a technical reason why you aren't able for users to modify DGs in Outlook -- that feature wasn't built into Outlook. Feature is only available in the ECP. If you want to disable the users from modifying DGs in ECP, you can turn it off -- But you can't turn it on in Outlook. http://technet.microsoft.com/en-us/library/ee332316.aspx I realize the document says that users can manage it from their email client, but it should be more specific and state that they can only manage it from the ECP. Andrea

Thanks for your inputs. Just to clarify... If I am not wrong, when exchange 2010 user modify the distribution group using outlook it runs the Add-DistributionGroupMember command in background and receive an error. [PS] C:\ >Add-DistributionGroupMember -Identity testdl -Member test@test.com The group "testdl" is not a mail-enabled universal group. + CategoryInfo : InvalidArgument: (testdl:DistributionGroupIdParameter) [Add-DistributionGroupMember], RecipientTaskException + FullyQualifiedErrorId : 28CDB980,Microsoft.Exchange.Management.RecipientTasks.AddDistributionGroupMember Does ECP work in same way as outlook to modify the group? If yes then why the command works when users run it through ECP not in outlook?

So why not make it a mail-enabled universal group?Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

Hi Su, I found a clue on google and it says: If you’re moving from Exchange 2000/2003 to Exchange 2007 or Exchange 2010, you’re going to want to convert all your domain local and global distribution and mail-enabled security groups to universal groups so they can be managed using the Exchange management tools. reference: http://www.evanhoffman.com/evan/2010/10/21/exchange-2010-post-upgrade-weirdness-cant-edit-mail-non-universal-group-or-security-group/ I think if you change the non universal group to universal group you still can edit the member via Outlook.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.

"Cause they're not universal" I'll go with that answer. The membership of a universal group is stored in the GC partition. If it's not universal, you have expansion server ugliness to deal with; please, if you masochistic tendencies, feel free to use non-universal groups. If not, then do consider universal groups. J

I agree with you all they are not universal that's why i am not able to edit using outlook but my question is why i am able to do it using ECP? can anyone point a reason for that?

Hi Su, I found a clue on google and it says: shouldn't Microsoft employees be using Bing? ;) As described above, Exchange 2010 should only use universal type groups for distribution lists. This is because Exchange is a forest-wide technology and this is the best group for forest-wide things. The ability to edit group membership is somewhat new in Outlook, so the Outlook team probably just built their product around best practices. The Exchange tools are more powerful and flexible, as they should be; you are the administrator who may have reasons to deviate from best practices. Not sure what the actual question is though. Just use Universal Groups. The only legitimate apprehension of using universal groups is in large, multi-domain environments where replication is an issue. Mike Crowley Check out My Blog!

In my opinion… Outlook uses Add-DistributionGroupMember to modify members, when we run this command against a non-universal group it results error which explains why we are not able to modify a non-universal group in outlook. [PS] C:\>Add-DistributionGroupMember -Identity testDL -Member test@test.com The group "testDL" is not a mail-enabled universal group. + CategoryInfo : InvalidArgument: (TestDL:DistributionGroupIdParameter) [Add-DistributionGroupMember], RecipientTaskException + FullyQualifiedErrorId : 28CDB980,Microsoft.Exchange.Management.RecipientTasks.AddDistributionGroupMember The Exchange Control Panel uses Update-distributiongroupmember command to modify membership, this command works for both Universal and non-universal groups hence we are able to edit both universal and non-universal groups using ECP. Can anyone from Microsoft correct me if my assumption is wrong?

Perhaps the reason is that ECP is different code from Outlook and less restrictive.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."