Restrict users from creating Personal Microsoft Account using their Corporate Email

[Mary_Yvette]

Good day!

How can we restrict  users from creating a personal Microsoft account using their Corporate email account. We have a user that was able to send using his personal account. 

Ex. Scenario

Company Microsoft Account: user@contoso.com

Personal Microsoft Account: user@contoso.com

User sign-in to Outlook live using his Personal Microsoft Account and was able to send email using the user@contoso.com

Hope someone could help us with this. Thanks!

[#2 · Accepted solution]

@Mary_Yvette 

Hello,

Have you tried this by yourself? this is not working since 2018

https://techcommunity.microsoft.com/t5/azure-active-directory-identity/cleaning-up-the-azuread-and-m...

I tried again today and got this message:

[#3]

@Alireza Rahimifarid 

Thank you for this!

What I have tried is sending an email using my Personal Microsoft Account in Outlook live. Which I created before the restriction. If that is the case for users that have created their Personal Microsoft Account before, can we restrict them sending email using their corporate account?