I am on a PC using outlook 2011. My wife is on a Mac, using outlook for Mac (the most recent version). We have both used outlook for years with no problems, sharing calendar "invites" with no problem. Something has changed recently, and we cannot figure it out. My wife can send me invites and they come in just fine, saving to my local outlook. However, when I send her an invite, it sends like normal on my end, and yet does not come into her inbox looking like a normal invitation...it simply shows the heading I entered on my calendar, but looks more like an email (see attached screen shot). There is no option for her to accept the invitation as it has before. So, she cant accept the invitation and cannot add it to her local calendar.

What setting could have been changed here?

Thank you.