Calendar app sending phantom invitation e-mails
I just started a new job with new email address, new calendar, etc, and am using iCal and the Mail app to manage my calendar and contacts. About twice a day (usually I'm not even looking at my computer or calendar in any way) my mail account will send out an invitation to an event I'm attending (not an even that I host or created--I'm just an attendee among other attendees). It sends out an invitation to an event that everyone's already been invited to--without changing any of the details, it just sends out another invitation. Sometimes these events are in the past.
This is EXTREMELY embarrassing because our clients get these invitations, which I did not intend to send. The only preventative measure I can figure out is to disable calendars on that e-mail address, which makes the rest of my job pretty difficult. Please help!
MacBook (13-inch Mid 2010), OS X Mountain Lion (10.8.4)