Microsoft Outlook Calendar Integration - do the emails only go out to Primary Email Address?

Microsoft Outlook Calendar Integration - do the emails only go out to Primary Email Address? If the Primary Email address is set as Home Email or personal email, will the ILT Microsoft Outlook Calendar Integration emails go to those (Home / Personal) email addresses too?

Business Use Case: If a learner does not have a work email address, and has Home or Personal Email address as Primary Email. In this case, does the learner get the Microsoft Outlook Calendar Integrations on their non-work Email address