 Dominic says, sometimes you need to send an SMS to somebody, but Apple won't let you because it believes that your contacts mobile number is valid for iMessage. Yeah, I've seen this. If people move from, like, you know, iMessage to or from Apple to Samsung or sometimes somebody on an Android phone gets a new number. And for whatever reason, Apple thinks that it's in the iMessage system, whatever. I've seen this. To do this, to solve this problem, to send an SMS when Apple wants to send it as an iMessage, go into Settings, Mobile Data and temporarily turn mobile data off. You can then message your contacts mobile number and it will definitively be sent as an SMS. So I could even send an SMS to you by doing this, John.