APM - Cross domain support

Thanks for the response. I have crossed this path above but the business required the external users from DomainB to NOT knowing their domain name or email address via UPN. If it was domainA trust domainB, then I can just do AD query against domainB and tell domainA users to specify their UPN logon. I think the easiest solutions is to keep the same policy with different landing URI, but redirect the logout session to a hosted html page that has links to different landing url.