1What it is
Reply-dnd-router checks replies from every channel and sends each one down the right path. Router means it sorts the reply: STOP, UNSUBSCRIBE, or QUIT turns on DND, the system's do-not-contact setting; HELP returns business contact information; YES flags a warm lead; other replies pause follow-up and hand over the conversation.
2Why it exists
The other workflows can only be useful if they stop when a person answers or opts out. Without one shared reply rule, someone could keep receiving automated follow-up after the real conversation has already started.
3What you'll see happen
Most of the work is silent. You will see alerts for positive replies, conversations waiting for a human response, and opt-out confirmations for people who ask messaging to stop.
4What you do
Nothing to route or honor opt-outs. Respond to the live conversations and positive-reply alerts that the workflow hands to you.