Hi, I've actually tried to run a similar (and now completely shut down) service a few years ago. If you look at my github I have several public iMessage-related projects. The biggest thing I ran into was getting my services rate limited or even blacklisted from iCloud for large periods of time when attempting to scale up. At low scale things worked fine and I am still running some iMessage bots (similar to classic IRC bots) for group chats with some friends without issue.

The only way I was able to mitigate rate limiting and black listing was to use actual physical Macs, only host a low number of users on each Mac, and put each Mac on its own physical internet connection. I also had to rate limit users and prevent them from sending the same message to many recipients as that would cause the machine to get blacklisted. Because of this I determined it would be nearly impossible to scale up without charging exorbitant amounts of money, which you seem to have avoided with your $20/mo rate which seems very reasonable.

Can you share answers to any of these. Totally understand if some of these are secret sauce and you can't answer:

- how you are preventing or mitigating blacklisting and rate limiting?

- what are you doing to detect when you are blacklisted?

- what is your remediation once you've detected that you are blacklisted?

- how are you handling scaling up your numbers of users?

- how are you sending/receiving the messages? (I'm curious: did you write your own solution that talks to iCloud services or are you abusing Messages.app and its corresponding SQLite database?)

- has anyone from Apple contacted you? are they okay with it?

Anyways, cool service, good luck!