Agree with Ben. For those of you like me that did not see this and tried it anyway here are some of the errors I saw. Hopefully they will make this post more findable as I did a search and did not find it. On the Unified Accounts Messaging Status page: Currently, this user does not have an SMTP proxy address that matches the Exchange email address that you specified in the Account Information section. We recommend that you add an SMTP proxy address so SMTP messages sent to the Connection server and addressed to the Exchange email address can be routed to the corresponding Connection user. And when trying to add an SMTP Proxy Address tot he user: SMTP address email is already configured on this object
... View more