Yes, you can have multiple Lindy’s communicate with each other.
Needs to be from the same account though.
You could also use webhooks to communicate with another Lindy using a second account.
Hmm you can have it reply back by doing the same thing. Add a message received trigger to Lindy #2 + Send a Message step for Lindy #1 - but that sounds like you are enforcing a loop here so be careful 😄 Make sure they actually know when to stop messaging each other