Usualy domain users use there domain credentials (
firstname.lastname@example.org) to login to their SharePoint online (Office 365).
Now there are another users from another company (domain) which try to login to this SharePoint online. They have to use
firstname.lastname@theDomain.onmicrosoft.com to be able to login successfully. Now they think the user name is too long and want to skip entering
Is there a way to skip writing
I read this article, however I think we need to have SSO on.