How to check if email is already registered in Microsoft 365?

[Maciej Kukułka]

Hi,

We want to invite partners to company's intranet. Instranet is working on SharePoint Online. As I know only e-mail addresses registered on Microsoft (free Outlook account or Office 365 account) can login to SharePoint. 

Is there any way to check if our partner's email is already registered on Microsoft?  

[#2]

Hi @Maciej Kukułka ,

I never had any experiences like this, found nothing on google, maybe it's not possible due to GDPR.

Maybe anyone else have a different answer :D

Best regards,
Schnittlauch

"First, No system is safe. Second, Aim for the impossible. Third no Backup, no Mercy" - Schnittlauch

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[#3]

Hi @Maciej

The question is no. You must to ask to be sure.
But you can send an invitation to collaborate to your SharePoint.
If the partner are a "Microsoft 365 or Office 365" license linked with the email address then He must to connect to your SharePoint and this user becomes a "B2B" partner.
If the partner are NOT a microsoft account, he must to create a "Microsoft account" with the same account with which you have sent the invitation.
This approach is from a "User" point of view. It is quite possible to set up strong B2B solutions between collaborators with or without Microsoft solutions.
Will depend on the scenario you need ...