Have you run into any rate limiting on iMessage? We usually see bulk messaging (eg: appointment reminders) getting silently dropped by carriers if over 100 messages are sent from that number in a day.
Additionally, what stops Apple from breaking your service, like so many other unofficial chat APIs?
Yup great callout, something we think a lot about. We haven’t run into any rate-limiting yet, though are aware that it’s a possibility. iMessage returns the date_delivered which has been valid and we send an SMS in those cases.
As for Apple shutting us down, it is a valid concern, although right now the service looks no different than if one were to type out a message on their own device.
Happy to share more details and go through any concerns you might have - maybe there's ways we can help with appointment reminders!
Additionally, what stops Apple from breaking your service, like so many other unofficial chat APIs?