Forum Discussion
Adding guests to an O365 group - email vs. UPN
Hi I have experience with huge confusion around how to add an O365 guest that is apart of another O365 instance. The guest's email address and UPN (User Principal Name) is not always the same, so...
AFAIK In office 365, when you are change your primary email address, it will automatically change your user principal name and sign-in name and same like when you change your user principal name then it also change your primary email address and sign-in name
so I prefer add your guest user's primary email address