Is there a way to send mass Outlook calendar invites?

Question

Our business is a subscription based business that has multiple service lines that hold a client only webinar each month. One of our service lines has found great success in terms of response and attendance sending out calendar invitations via Outlook.
However, these invites can only be sent out to 20-30 email addresses at once without being marked by spam filters.
1. Is there a way to do this in outlook or a product that allows us to do this?
2. Is there a way to do a "mail merge" of sorts for outlook invitations?
3. I know we are able to do a mail merge and attach an .ics file, but correct me if I'm wrong, we aren't able to verify who added that to their calendar because the sending email address won't receive an accepted or declined response. It would be
nice to see who accepts as well because then we are able to cross reference our registration list and manually register those who may have just added the calendar request, but didn't go into the link to register for the conference--this also gives us collateral
for sponsors.
Any ideas would be very helpful. Thanks!
PS - Most users are on either Office for Mac 2011 or Office 2010.
Oliver Pugh Information Systems Administrator Healthcare Business Insights

Answer 1

Please have a look at the suggestion in the below thread (answered by Diane) to overcome the spam issue.
http://answers.microsoft.com/en-us/office/forum/office_2010-outlook/spam-creates-appointments/56e6ad96-5060-4a81-ba33-2b7e1621a349
DeVa, M.S., {MSFT} Please remember to mark the replies as answers if they help