Send a Text Message with Alexa
You can send a text message with Alexa if you are an AT&T customer. You need to enable the AT&T Send Message skill in the Alexa app.
Once this is complete you need to add up to 10 contacts to your account using the service after you verify your account. You'll need to verify by logging in to your account or sending a text message.
Once set up, say, "Alexa ask AT&T to text Adam Mills." When prompted you can speak your message to the Amazon Echo or Echo Dot.