Within the Regroup system you are able to send text notifications and receive responses allowing for two-way communication.
The responses can be directed to the sender of the message, all administrators, or members of the group. Once you receive a reply the response will include the phone number of the person responding and the notification they are responding to. This data is available on the Text/SMS reporting page.
Two-way texting can be enabled on a group by group basis. Just go to the Group Settings Page and select Text Settings.