tl;dr Corporations are used to email and see no reason to change it, email (Outlook) just gets more plugins as new things emerge. Maybe I'm old fashioned but I

tl;dr Corporations are used to email and see no reason to change it, email (Outlook) just gets more plugins as new things emerge. Maybe I'm old fashioned but I see no point in trying to replace email. It is an app just like everything else and any serious application should have some form of email integration.