From Field in New Message Pre-populate Shared Email

[cakahl]

I just setup a shared mailbox for several users in our organization.  Everyone is accessing it and functioning without any problems. However, I noticed that on my own Outlook, on a different shared mailbox from the one I setup for the users, when I click the From field, the shared mailbox is already there in the list and I don't have to hit Other Email Address to search for it. This new shared mailbox isn't showing up in the From list like mine is and is frustrating the users that they have to search for it every time.  How does one get the shared mailbox to show up like that? Or does it just happen automatically over time with continued use?  Here's a screen shot of my Outlook's From drop-down. The shared mailbox is circled in red.

[#2]

This depends on how you've added the shared mailbox in Outlook (additional account vs additional/automapped mailbox).

[#3]

@Vasil Michev They are just automapped. 

[#4]

That's the expected behavior then. You either need to add it as additional account (File -> Add account) or use third-party add-ins that allow you to change the From address.