Updated Requirements for SMTP Relay through Exchange Online

I feel like nobody who works at Microsoft on Exchange has any clue how many of us are part-time Exchange admins, and that Exchange is just a tiny part of our day-to-day work.

Now I have to wait for someone to break this down into simpler terms to figure out if it affects my organization or not. So frigging annoying.

For what it's worth - here is our scenario. Maybe someone can chime in on whether or not I have to change things up.

We have an on-premise SMTP server, the one that comes with IIS. All of our internal equipment and servers send mail to that address. It's then sent along to Exchange Online with an account email address removed for privacy reasons. We set up the "send on behalf of" properties so that we get those emails like email address removed for privacy reasons  and mailto:email address removed for privacy reasons.

So everything is sent as our domain name. So that means we're good? Again - Exchange is a tiny part of my day. I don't know everything about it to be sure about all this.