Calendar Invites Not Sending
A few months ago, myself and my family began encountering issues with iCloud Calendar invites. Suddenly, they would no longer send to anyone. It showed it as sent, but the recipient never received an e-mail nor notification (all set to In-App Notifications in iCloud Preferences). This is on devices running latest iOS 10, 10.1, and 10.2 (as time as passed). It also affects our Macs (running latest each of El Capitan and Sierra), as they do not receive or send invites either. It doesn't matter which device (or account) you start the process on. They all exhibit the same problems. Multiple iPhone and iPad generations, as well as 7 years of Macs.
To eliminate issues commonly found online:
One user has a Gmail address as their AppleID.
Another receives e-mail on a private domain e-mail server with their AppleID a different Gmail address.
I have a @me.com address as AppleID.
I've logged out of iCloud on all devices to reset. No change.
The issues with it not working at all seemed to start around when iCloud Calendar invite spam began hitting the news. Never received any spam, just lost ability to do invites.
Is anyone else experiencing this problem?
iPhone 7, iOS 10.2, 32 GB, Black