.net - Exchange Mailbox Delegate Access for a security group via EWS or PowerShell -

Currently, I delegate support group went on to delegate access section mailbox through Outlook,, and permission levels set Want to

I want to automate it, but there is no way that works for the group.

The following PowerShell will add a group, but only set folder permissions that are not included in the group as a representative

  Ed MailboxFolderPermission -Identity "Mailbox: \ Calendar ". -User "group" -AccessRights Editor  

The following NAT address EWS user will add accounts in the same way, like I want to add a group. If I add a group to the list, then it will fail, yield the following error: "The representative does not map to any user in Active Directory."

  public function Setaditr (string as mailbox, listDelegates System.Collections.Generic.List (= false dim listDelUser as as a string)) Boolean Dim setEditorResult Boolean The new list (DelegateUser's) listDelegates each strDelUser string as the DelegateUser = in the slow delUser for the new DelegateUser (try strDelUser) as DelUser.Permissions.CalendarFolderPermissionLevel = DelegateFllerPermissionLevel.Editor ListDelUser.Add (delUser) Next slow Reactions as collection (copy Idi user reports) = service. Jodendilegets (New mailbox (mailbox), meeting spaces Dilivrispok. Further, the catalog Dielughr) respondents in feedback as a representative for each reaction response if North .Result = 0 then setEditorResult = True Else 'log error dim final String = response .ErrorMessage As the end, then the next catch precedence as the 'Log Error Error end try the SetEditorResult End Function function  < / Pre> 
 Does anyone know of a way to do that works for security groups? Thanks! 
 
 Update 10/31/2014 
 
 I have found ways to add security groups as reps and their permission has been set correctly. 
 
  set -Mailbox -Identity "MAILBOX" -GrantSendOnBehalfTo "DELEGATE" Ed MailboxFolderPermission -Identity "MAILBOX: \ Calendar" -User "DELEGATE" -AccessRights Editor  
 
 for many delegates, use the following: 
 
  set-mailbox -Identity "mAILBOX" -GrantSendOnBehalfTo @ {Add = "DELEGATE1", "DELEGATE2"} add MailboxFolderPermission -Identity "MAILBOX: \ Calendar" -User "DELEGATE1" -AccessRights editor add MailboxFolderPermission -Identity "MAILBOX: \ Calendar" -User "DELEGATE2" -AccessRights reviewer  
 
 Unfortunately, I still  A representative for the representative check Sta has not been able to find me receives copies of meeting-related messages sent.  Checkboxes for security groups.