When using the AllowAccess method of either the File or Folder objects, you cannot specify the domain of a valid group account:
Specifying a group account with its domain will cause the following run-time error:
oFolder.AllowAccess "MyDomain\Everyone", 1024
No mapping between account names and security IDs was done.
If the group account is specified without the domain,...
oFolder.AllowAccess "Everyone", 1024
...you will not receive a run-time error. However if multiple domains containing a group with this name are available, the domain for this group acccount will be assigned at random.