EMS 2010 commands:
Get-DistributionGroup –ID “DistributionGroupName” | Set-DistributionGroup –ForceUpdate
To “upgrade” all Distribution Groups within an Organization, the following command will do the trick:
Get-DistributionGroup –ResultSize Unlimited | Set-DistributionGroup –ForceUpdate
I have heard heard reports of substituting -ForceUpdate for -ForceUpgrade working as well.
While the commands above appear to “upgrade” Distribution Lists from Exchange 03/07 to Exchange 2010, I can’t find any Microsoft documentation explaining why this should be necessary. I surmise that simply touching a Distribution Group using an Exchange 2010 Administrative Tool (whether it’s the EMC or the EMS) may update or add an attribute to the object making it fully functional within Exchange 2010. If anybody has additional information please feel free to leave a comment and share.