How to fix conflicting proxy addresses in O365 when creating a mailbox
The proxy address is already being used by the proxy addresses of another mailbox Why can’t I create a mailbox at account@domain2.com if one already exists at account@domain1.com The Problem So, you have two (or more) domains associated with your Office 365 Exchange account. When you try to create a shared mailbox on one domain, you encounter an error stating the proxy address is already being used. For example You have two domains, lets call them domain1....