It does what you asked. All they have to do is to open the one they wish to
have it added to their calendars. You never said that you wanted
notification of their acceptance.
Just to jump in on the thread - what good does it do for people to be
able to make a choice between meeting dates if the sender does not
know of the recipient's decision? I understand MS feels that everyone
should be on an exchange network and actually use the calendar feature
with Outlook, but some old dogs are not going to learn new tricks. We
want to be able to poll for a meeting time that works best - cannot
use Voting Buttons since you cannot make multiple selections. Are
there any other solutions? If not, we will just continue to use the
full functionality of the Exchange Server and Outlook to send text
emails.