Hi All,
In our environment we have a few Mailbox users for who the e-mail is forwarded to a external E-mail address. Normally you would create a mail contact and set the external SMTP address on the contact. In the mailbox settings from the mailbox user you would set to deliver to that contact en choose if all e-mails should be delivered to both the mailbox and the contact or just the contact.
The whole option to forward to contacts is missing in Exchange 2013. There is only the option to enable forwarding to Mailbox user and Mail users but not to Mail contacts. (Open mailbox, go to Mailbox Features, scroll down to Mail Flow and under Delivery Options click View details)
The big difference between a Mail Contact and a Mail User is that a Mail User is provided with a AD username/password. A Mail Contact is just a AD user item.
(http://technet.microsoft.com/en-us/library/bb201680.aspx)
Yes you can still forward e-mail from a Mailbox user to a external address with PowerShell:
Set-Mailbox -Identity "John Doe" -DeliverToMailboxAndForward $false -ForwardingSMTPAddress john@doe.com
But this forward can't be managed trough the ECP or trough a Mail Contact.
Thanks all, I'm very curious what your findings are on this topic.