We have the following scenario:
Company A
Forest = CompanyA.com
Domain = CompanyA
Email Domain CompanyAX.com
Users' UPN = CompanyAx.com
Company B
Forest = CompanyB.com
Domain = Corporate
Email Domain = CompanyB.com
Users' UPN = CompanyB.com
There is a inter-forest trust between the 2x forest already.
We plan to install 1x AAD Connect to link up the 2x Forest.
The 1x AAD Connect will link up to 1x O365 tenant.
Email domain of the O365 tenant will be CompanyC.com
I think the above is doable.
However, I couldn't understand once the 2x forest sync up to Azure AD, what will the users use to log on to O365?
Can they still use their original UPN like joe@CompanyAX.com and joe@CompanyB.com?
Or all of them need to use joe@CompanyC.com?
Hope someone can enlighten me. Thanks heap!