To enable auto-response for incoming messages, simply:
- Click the cog wheel in the upper right and click “My Settings”
- Scroll down to the “Message Settings” section
- In the box under “Auto-Response to incoming messages” enter the message (with a max 160 characters) that you would like to be automatically delivered to incoming messages
- The message will automatically save
Keep in mind that the auto response messages do count against your usage.
If you were the last person to text and receive the auto-response, you will not receive it again.