Why can't I get my meeting planner on my Sony Z3 email app to get recognized and be added to the calendar?

[AC Question]

meeting planner on Sony z3 email app is not recognized and cannot be added to the calendar

I have my own domain and use the related email with imap, without calendar support
Is there a way that meeting planners are recognized and added to the default calendar in my Z3C Sony?
I could do that in bb and iPhone without having exchange server
Thanks