When you create a bulk invite for Azure AD business-to-business (B2B) collaboration users, the two essential parameters that you must include are the email address and the redirection URL. The email address is necessary to identify the external users you want to invite, and the redirection URL specifies where the invited users will be taken once they accept the invitation. The other options such as username, shared key, and password are not required for the bulk invite process.

Mail-enabled security groups (MESGs) in Azure Active Directory can only contain members that have a mailbox. This includes licensed users, shared mailbox identities, and other mail-enabled security groups. It does not include unlicensed users or groups that are not mail-enabled. In this case, only User2 has a Microsoft Office 365 Enterprise E5 license, which includes a mailbox, making User2 the only eligible member for Group3. Consequently, User2 is the only object that can be added as a member to the mail-enabled security group Group3.






Configuring password writeback ensures that when a password is changed in Azure AD, the new password is written back to the on-premises Active Directory. However, this does not affect the immediacy of account disablement synchronization between Active Directory and Azure AD. To prevent a disabled user from authenticating to Azure AD immediately after the account is disabled in Active Directory, other measures such as configuring Azure AD Connect to use Pass-through Authentication (PTA) or implementing an immediate synchronization process would be necessary. Therefore, configuring password writeback does not meet the goal.