Are there limits to the number of MMS or SMS recipients on a message?

Most carriers do impose a maximum limit on the number of SMS/MMS recipients as the carrier's system is the one processing those texts. AT&T restricts it to 10 maximum, and I image most other carriers are similar.

I don't know if there is any limit on iMessage recipients though.

While I certainly agree with you in principle, I'll just mention that I've been with AT&T for over a decade now and they've always had the limit of 10 and there have been plenty of posts in their own web forums asking it be removed. They seem to simply ignore any and all such requests.

Bwhite357 wrote:

Thank you for the prompt response. I pay them enough money to not have a limit on groups of messages.

I suspect AT&T doesn't want to be dealing with (any more than they already are) complaints about people being spammed by robo-messages. For now, I get far less spam through SMS than I do through email. I think that's partly due to the fact that it's harder to send them out in bulk. I, for one, am in favor of that.

If you need to do larger group messaging, I'd recommend one of the dedicated apps. I've used both GroupMe and Telegram with good results.