Why does my imessage send as text message

- Why does my imessage say send as text message
- Why did my imessage send as text message
- Why do my imessage send as text message
- Why does my iphone send as text message instead of imessage
- Why does my message send as text not imessage
- Why would my imessage send as a text message
- Why does my message send as text instead of imessage