Exchange Online does not support Guest users. To share availability with external users, you need to configure either a sharing policy (for individual sharing) or org relationship (broader, tenant-wide sharing). Details are here: https://learn.microsoft.com/en-us/exchange/sharing/sharing
Let guests to see room availability and to book a room
IMK
401
Reputation points
Hi
We have added meeting rooms as room resource in M365 Admin Portal.
What are my options to let external guest persons to see a room availability (free/busy) and to let these external guests to book a room?
These people belong in another M365 tenant and because this is a temporary situation, we would like to keep this as simple as possible.