We have embraced federated messenger and see the value it brings to the org, but have issues getting our MSP to engage through it. We have a small IT staff so leverage Managed services for various aspects. While those MSP individuals act as members of the team, they must manage work through a ticketing process in order to track efforts and are afraid IM will bypass that process since anyone can add them to space once the email address is known. To address this we want the ability of just server admins to directly IM the MSP's Server POC's but no one else in our org - we dont want anyone else to direct message or add them to new spaces - basically block the ability to invite/message beyond the select employees. This is one team, other teams would work the same way with their MSP POC's.