How to deliver email generated by Microsoft 365 apps(Sharepointonline/Stream/Teams) to O365 email

How to deliver email generated by Microsoft 365 apps (Sharepointonline or Stream or Teams) to O365 Mailbox internally, instead of delivering to external mail gateway like IronPort or Proofpoint ?

Here, the sender and recipient from the same Microsoft 365 tenant or same domain users.

Thanks in advance.