I’m ignorant. What does native exchange support mean? I know we can get outlook/hotmail etc but is this more of the enterprise support?

What the hell is happening with this cats chest?

Yes, it’s secure and of course can be further secured by other services, like vpn and scanners and such. I front my stuff with Cloudflare certs on their free tier as well.

Just use complex passwords for the admin and logins. They also support two-factor authentication which is easy to setup.

I like Bitwarden because I can host my own server and control it all. Not sure if the other service does set-hosting. Maybe you can do the same with that?