We have several domain groups that are not showing up in our SharePoint 2010 environment. The common thread seems to be that domain groups without an e-mail address assigned to the group are the ones that don't show up in SharePoint. Domain groups that do have an e-mail address assigned to the group appear in the lookup lists and are validated successfully. However, if the domain group does not have an e-mail address assigned the domain group does not appear in the lookup lists and the validation fails.
Has anyone else experienced this issue? Is there a way to get past this?