Use the Messages app at the top of the screen to start a new message, or tap an existing message.
Touch and hold a conversation, then drag it to the top of the list.
You can unpin specific conversations at the top of the Messages list.
Do any of the following:
Touch and hold a conversation, then drag the message to the bottom of the list.
Touch and hold a conversation, then tap How to use Messages for Business.
Note: Messages sent to participating businesses appear in dark gray, to distinguish them from messages sent using iMessage (in blue) and SMS/MMS messages (in green).