It indicates that the message was sent as sms/mms instead of imessage.
Iphone green message doesn't say sent as text. You need to rely on sms to send. Web if your iphone messages are green, it means they're being sent as sms texts rather than imessages. Web first, make sure you have the latest version of ios on all your devices (settings > general > software update).
Apple nags you to install the updates,. Choose the option “send as a text message.” Delivered & read messages depend on whether the recipient has ' read receipts' switched on or off.
Web if you see a green message bubble instead of a blue one, then that message was sent using mms/sms instead of imessage. Web sometimes, you may see your text messages to another iphone changing to green. Web green is sms.
You can undo a recently sent message for up to two minutes after sending it. Web tap and hold the message you sent (if it says “not delivered,” tap the little exclamation mark next to it). Web send as text message instead of imessage.
You'll always see green when texting android users, or when you're not. If it is already on, turn it off and on again. If the person you're contacting doesn't have an apple product, imessage won't work.
Web select settings > general > date & time, then move the set automatically switch to on (green). You cannot force a read. There can be several reasons.