Hello,
We have 90 devices which are in numerical order, i.e. myemail55@icloud.com, myemail56@icloud.com
For 86 of the devices these emails have gone through fine from the app center SMPT Service, so the emails are getting through most of the time which is why I don't see why it could be gettign caught as spam as the accounts are all set up in an identical way.
We are currently reconfiguring the devices from scratch, but I don't think that will affect this issue as it is the icloud account itself (after checking online) which is not receiveing the pushed emails...
I am wondering if it was due to the invites being sent form app center before the email accounts were fully provisioned, and now when resending the invite the app center isn't managing to push them through properly.. Although I have deleted the invited user account and re invited so that should have theoretically sorted that.
I will also try creating another alias on the same iCloud account, and deleting the iCloud account to free up that email address to try again.....
very baffling...