Cozi calendar daily and weekly email reminders not being delivered to @me or @ iCloud email address

I installed the Cozi app in September 2017 and set it up to email me my calendar events daily and weekly. Abruptly on October 22, 2017 I stopped receiving them. I uninstalled and installed the app. I updated both the Cozi app and iPhone to current versions. I added Cozi to my list of contacts. The emails are not in my junk box. I contacted Cozi who said they are sending the emails but Apple is not releasing them as they have been contacted by numerous Apple users. Cozi is a shared calendar so we found that the reminders continue to be sent to family who have a @gmail email account. I contacted Apple who stated it was not there problem. I don’t know why the problem exists. Please help. Thank you.