After you have upgraded your Exchange installation to Exchange 2010 and you might want to use the new distribution group features, you will see this “error”:
“You don’t have sufficient permissions. This operation can only be performed by a manager of the group”
You might also notice that it’s quite difficult to add a manager to the group from the Exchange management console.
The reason for this is that the group needs to be upgraded to Exchange 2010.
You can do that with the below command, which will upgrade all the distribution groups you have.
Get-DistributionGroup | Set-DistributionGroup
If you want to set the Manager for all group to the same use – you can use this command
Get-DistributionGroup |Set-DistributionGroup -ManagedBy “Manager Username” –BypassSecurityGroupManagerCheck