When sending a meeting request to all people in our firm, we are getting tons
of complaints that their calendars are being "hyjacked" and the meetings are
appearing in their calendars (even if they are just tentative) without even
having accepted the meeting.

Is there a way to send out a meeting request so that it is only added to the
individuals' calendars only once they accept?

We need to send these announcements to all people in our firm because most
people like to be aware of upcoming meetings/training sessions, even if they
are not going (they like to know what training their subordinates may be at),
but this is a real problem because the partners of the firm (who aren't the
most computer literate, and don't always have the time, or interest (you
know, they are multi-billionaires!), to check these meeting announcements.

Thanks!