What is a Guest User?
Guest users can attend meetings, view documents and chat in Teams they're invited to. Once a user shows up in the Guest users list, you can remove their access there..
To view guest users in the Microsoft 365 admin center, expand Users in the left nav and then choose Guest users.
Can Guest Users be used in the Microsoft integrations with SSO and Teams?
Yes! Ensure that your guest users have a First and Last Name set in addition to the Display Name within the Entra ID system, otherwise they may not show in the list. They will appear with the long form guest address, user_guest.tld#EXT#@YourTenant.onmicrosoft.com