Hi @Dani Abouhamad , while this is an interesting use case, it may not be possible to achieve exactly as you described but we can try some things.
Here are some options you can consider:
- Use Azure AD B2B collaboration: You can invite external users to your Azure AD tenant as guest users and grant them access to the shared mailbox. When they sign in to the shared mailbox, they will be prompted to authenticate using their own credentials. This is not exactly the two-step authentication process you described, but it achieves a similar result.
- Use Azure AD Application Proxy: You can publish the shared mailbox as an application using Azure AD Application Proxy. When users access the shared mailbox through the published application, they will be prompted to authenticate using their own credentials. This is similar to the Azure AD B2B collaboration option, but it requires more setup.
- Use a third-party SSO provider: You can use a third-party SSO provider like Okta or OneLogin to achieve the two-step authentication process you described. You would need to configure the shared mailbox as an application in the SSO provider and configure the individual accounts as users in the SSO provider. When users sign in to the shared mailbox, they would be redirected to the SSO provider for authentication and then redirected back to the shared mailbox. This option requires the most setup and may not be feasible depending on your requirements.
Please let me know if you have any questions and I can help you further.
If this answer helps you please mark "Accept Answer" so other users can reference it.
Thank you,
James