In our company, we manage each other's calendars.  Zoho Calendar is a total mess for this use. There are several events each day and each event probably will have a few changes made.  No one uses email to keep up with their calendar, ever.  Having dozens and dozens of emails per day is not an option.  It seems Zoho is unwilling to allow users to opt out of any kind of invite or notification email.  It makes the calendar unusable and it's the last thing I need to move from Google.

I think the (not ideal) solution is to have everyone create some sort of filter so every invitation or update goes straight to the trash.  However, the emails come directly from the user who added an event or made a change.  I've combed through the html of emails tried several searches to try an hone in on those emails only, with no success. 

Has anyone successfully been able to filter all calendar emails and nothing else? 

Maybe you've found another solution?