Hi Lauren. I think I figured this out.
I share my calendar with my wife and two kids. One kiddo was upset he got so many calendar changes. The other didn't get any emails. From what I found, your colleague needs to do this in iCloud (I hope this is how you share calendars or I'm wrong!).
Once your colleague logs in to his iCloud account and goes to his calendar, click on the green 'broadcast' icon to the right of YOUR calendar (your calendar should be listed on the far left side of his iCloud calendar window). Once they do this, a pop-up window should appear and a check box at the bottom of the window says 'Email me when this calendar changes'. Uncheck that and they shouldn't get any more emails when you change times on your calendar. The downside is I don't think they'll get an email alert when you create an event as well.
I hope this helps.
I have the same problem, the recipients of 120 emails regarding changes to my iCal both had 'email me when this calender changes' unchecked so they shouldn't be getting emails in the first place. They've both shared my calender for years but only got the emails after changes I made yesterday March 15.
Brent Sloan wrote:
..... Uncheck that and they shouldn't get any more emails when you change times on your calendar. ....
Brent, unfortunately this does not solve the actual problem. Yes, "it should" help, but... The strange thing is that the problem just popped up since yesterday. Must have been a (hopefully not intended) change by Apple in their iCloud settings. The statement "It just works" is not really true at the moment. I hope that Apple gets aware of all these posts, and does something against it....