Forum Discussion
Cross AAD Tenant Identity setup for M365
This is a school setup, requiring 2 ADs for physical separation of corp user and Faculty/student users. M365 for EDU with F1 licences has been choosen, the school name to be use as the domain name. T...
Guest users cannot have mailboxes in another tenant. For your scenario, you need to either add all users to the same tenant (look into GAL segmentation and Information barriers for separating them: https://docs.microsoft.com/en-us/microsoftteams/information-barriers-in-teams) or use two separate tenants, with each user having a mailbox in their respective "home" tenant. Guest access can then be used to grant access to SPO sites or Teams.