In our current production with Office 365 Wave 14 OWA 2010. I can compose a new email and show the from field then choose other e-mail address and then select a shared mailbox that I have Sent on Behalf permissions for. When the email is sent, it shows to the recipient "My Name Sent on Behalf of Shared Mailbox Name"
I am trying to duplicate this in our wave 15 preview tenant and one of our wave 15 tenants that we have and when I show the from field I no longer have the option Other e-mail address. I right click the email address and able to remove and then I type the address if the mailbox I have Sent On Behalf of Permissions to and I cannot send it. I grant my self send as permissions and I am able to send but it shows as from the Shared Mailbox, no mention that I sent it on behalf of the shared mailbox. Is there a way I can accomplish what I can do in OWA 2010 or this functionality removed?