Marketing > SMS > Chat is a two-way inbox. The left column lists your customers who have a phone number, sorted with unread conversations first; a red badge shows how many unread texts each has, and the Search contacts... box filters the list. Click a customer to open the conversation: sent messages appear on one side with their status (queued, sent, delivered, failed, undelivered) and time, received messages on the other, grouped by day. The conversation refreshes automatically every few seconds. At the bottom you can type a reply, pick the From number, optionally set a Schedule time and click SEND. A profile icon next to the customer's name opens their customer record, and the header shows your balance with a Buy link. Opening a conversation marks it as read.