How to send as a Hidden Shared mailbox in Exchange Server
Let’s take a look at a requirement for a shared mailbox to be hidden and also be able to send as that shared mailbox
So, is it even possible to send as a hidden object? The answer is “No”. When we try to send as an object that is hidden it fails since the object is not resolved in the GAL
So how to achieve this
Let’s consider a shared mailbox Shared mailbox
This mailbox is currently not hidden from GAL
Now I am going to give send As rights to one and show that I can send As that user when the shared mailbox is not hidden from GAL
Now I am going to hide the Shared mailbox from GAL
Now let me try to sendAS the shared mailbox
How to make this work
Step 1: Unhide the shared mailbox from GAL, make it visible
Step 2: Go to outlook and search for the shared mailbox in Gal, right click that shared mailbox and add it to your local outlook contacts
Step 3: Again, hide the shared mailbox from GAL
This time it uses the Contact from the local address book and not the GAL, so it would work as expected
Ratish Nair
Microsoft MVP | Exchange Server
Team @MSExchangeGuru.com