Macos – How to stop Apple Mail from opening because of iCal appointments


I use only webbased Gmail for mail, but keeps popping up as a result from iCal-appointments that have a e-mail reminder setting. I also get these reminders from Gmail anyway and I would like to disable the program altogether.

I'm kind of fed up of doing "forcequit" from Alfred several times a day. How can I solve this? Is there some kind of hook like "When launches, kill it"? cannot be removed from OSX.

Best Answer

There's really only one way to kill (as per my comment on waiwai's answer). Open from Applications/Utilities and enter:

sudo chmod 000 /Applications/

This will prompt you for your administrator password.

To reverse this, enter:

sudo chmod 755 /Applications/

I originally thought iCal was using the Launch Services database to open Mail, but in order to get the communication working, it relies upon AppleScript instead. You can find the script here:


Unfortunately, it says:

… changes to this file will not be reflected in iCal behavior unless manually recompiled.

Thus you can't just delete or move away this file. You won't see any difference.