Posted 25 April 2017 - 02:08 AM
Are you sure the people you are trying to send an iMessage to still have iMessage set to the on position on their iPhone? Double check with them.
Also, keep in mind that iMessage requires a data connection for both you and the person you are sending the iMessage to. If the Apple system detects that either of you does not have a data connection, then it will send as a text message. So, if you (or they) temporarily lose your data connection (i.e. in a weak cell zone coverage...text messages can go in pretty weak areas, while cell data not so much), then you lose your ability to send an iMessage. When this happens, the place where you type your message will say "text" if there is an in ability to send an iMessage for whatever reason. If the place where you type your message says "iMessage", then it will try to send it as an iMessage...if it fails, it will then typically try to sent it as a text message. Generally, the system is better at detecting upfront when the sender does not have data connection. If the receiver loses their data connection, then it typically takes longer for the Apple system to "learn" that and pass that information onto you for when you go to type the message and see what the entry box says. This is why you might have it saying "iMessage", but then fail to send as an iMessage. Also, on your end, it is not just a lose of data connection, but a weak connection. In the case of a weak connection, the system might still believe you have a data connection, but when it goes to try to send the iMessage, it discovers that it the connection is not good enough and cannot send as an iMessage.