How to send an SMS in iOS 10 I just updated to iOS 10 and I want to send an SMS instead of an iMessage to a friend. In iOS 9 I could continuously touch an old message and press send as a text message (or something like that). Now in iOS 10 I don't see anything relevant.
So, does the other person have an iPhone or something else? If it's something else, then it will automatically send as an sms. If the messages fails to send, and you try multiple times to send it, it will ask if you want to send as an sms instead of an iMessage (at least I think it will still do that).

If anything else, you could always go into iMessage settings, sign out of your Apple ID and then turn off and on iMessage.