specific iPhone contact stuck as green messages, not reaching them

Hi there

Thank you for posting to Apple Support Communities.

We understand an iMessage contact is not working for you. Are you successfully able to communicate with others with iMessage?

Is your cellular data working correctly on your iPhone? Are you able to browse to websites?

Take a look here:

If you see a green message bubble

If you see a green message bubble instead of a blue one, then that message was sent using MMS/SMS instead of iMessage. There are several reasons for this:

* The person that you sent the message to doesn't have an Apple device.

* iMessage is turned off on your device or on your recipient’s device. To check if iMessage is turned on for your device, go to Settings > Messages > iMessage.

* iMessage is temporarily unavailable on your device or on your recipient’s device.

* You might need to update your settings for Messages after you set up a new device.

If you can't send or receive messages on your iPhone or iPad - Apple Support

If you're still having an issue, we recommend contacting Apple Support: Get Support

Take care.