If you use Apple’s Calendar app you may have been getting iCal invitations which are obviously spam, I have and so have many others including BBC’s Rory Cellan Jones.
— Rory Cellan-Jones (@ruskin147) November 26, 2016
The result is that your calendar starts to fill with invitations that are obviously spam, trying to sell you stuff!
The problem arises twofold:
Firstly you are unable to actually block these notifications, so can’t stop them coming in.
Secondly you are unable to delete the notifications, if you decline the notification then the spammer will get a receipt that your calendar is authentic, so you get a lot more spam notifications.
This all means that very soon the calendar becomes unmanageable and unusable.
The first thing to do is to set up your Calendar app to ensure all notifications of events come as e-mails and not as notifications in your calendar inbox. This is not as simple as it sounds as you can’t do this in the Mac or the iOS application, you need to do this on the web.
So go to iCloud.com in a web browser, this needs to be on a computer and not on your iPhone or iPad.
Select Calendar and then click the cog in the bottom left hand corner and select Preferences…
In the Preferences window select Advanced.
Under Invitations change Receive event invitations as: from the default In-app notifications to Email email@example.com. Though the dialogue says Use this option if your primary calendar is not iCloud you can also do this even if your primary calendar is iCloud!
There are two options for getting rid of the spam notifications.
You can create a special spam calendar that you can then add the spam notifications to, and then delete the calendar.
Create the new calendar and the tap on the spam invitation and tap calendar and select your new spam calendar. You can after doing this delete the new spam calendar along with all the spam notifications.
The method I used (which was before I knew about the previous method) was to decline the spam invitation (I was lucky that I only had two or three) and then delete that calendar merging the events with an existing (or you could create a new) calendar.
Hopefully Apple will release a fix for this in the near future.