I would like a final message to go from the Conversational AI bot to the contact when the maximum number of replies is reached.

The AI assistant should not be having a two-way dialog with someone and then suddenly go silent.

In the Conversation AI Advanced Settings for Auto-pilot mode there should be at least 2 fields for what happens when the max number of messages is reached:

1 - What do you want the bot to say before it goes to sleep?

(Example answer: "Thank you for providing this information. It will help us determine how to best serve you. I will hand this conversation over to a human who will get back to you shortly.")

2 - What happens next?

Possible options:

Trigger a workflow.

Notify the assigned user.

Nothing (leave conversation marked unread).

Mark the conversation as read.