You can create a rule to forward to a bcc'ed distribution list.
Edit 2015 02 23
While the above is technically true. It is not as simple as I thought. There is no bcc option in the dialog box for addresses when forwarding by rule. My version is 2010.
You can set a bcc in a rule with a run a script option rather than using the dialog box.
Sub Forward_BCC_DL(item As Object)
Dim newForward As MailItem
Dim myRecipient As Recipient
If item.Class = olMail Then
Set newForward = item.Forward
Set myRecipient = newForward.Recipients.Add("Name of Distribution List with the quotes")
myRecipient.Type = olBCC
newForward.Display ' Comment out with a leading apostrophe once tested
'newForward.Send ' Remove leading apostrophe once tested
Set newForward = Nothing
Set myRecipient = Nothing
Private Sub Forward_BCC_DL_Test()
' To test
' open a message then run this code
Dim curritem As Object
Set curritem = ActiveInspector.currentItem
If you are not familiar with VBA this will be helpful.
Getting Started with VBA in Outlook 2010
How to use Outlook's VBA Editor
Edit 2015 02 23 - End
Edit 2015 02 24
It is probably better to create a distribution list as used above but this will slowly retrieve all contacts.
Sub Forward_BCC_All(mail As MailItem)
Dim ContactsFolder As folder
Dim Contact As Object
Dim objMail As MailItem
'Dim j As Long
Dim objRecip As Recipient
Set ContactsFolder = Session.GetDefaultFolder(olFolderContacts)
Set objMail = mail.Forward
'j = 0
For Each Contact In ContactsFolder.Items
'j = j + 1
'Debug.Print j & ": " & Contact
Set objRecip = .Recipients.Add(Contact)
objRecip.Type = olBCC
'Debug.Print "Resolving contacts slowly"
Set objMail = Nothing
Set ContactsFolder = Nothing
Set Contact = Nothing
Private Sub Forward_BCC_All_test()
Dim currItem As MailItem
Set currItem = ActiveInspector.currentItem
Edit 2015 02 24 - End