Think about integrating calendars, corporate contacts (from AD), handling RSVP replies said mx server receives and updating the calendar server, securely deal with modern auth (+ legacy krb5 auth, yuk). It's a huge hassle and everything except Exchange only handles 80% of this.
Modern expectations now want: web clients (OWA), todo lists, integrated storage (SP/OneDrive), and push notifications to any phone from any vendor.
So yeah, the only on prem solution is still Exchange.
alt Hacker News
Not easy at all.
Think about integrating calendars, corporate contacts (from AD), handling RSVP replies said mx server receives and updating the calendar server, securely deal with modern auth (+ legacy krb5 auth, yuk). It's a huge hassle and everything except Exchange only handles 80% of this.
Modern expectations now want: web clients (OWA), todo lists, integrated storage (SP/OneDrive), and push notifications to any phone from any vendor.
So yeah, the only on prem solution is still Exchange.