This happens when Connect can't find an email address for the agent assigned to the renewal. Some management systems don't store agent email addresses at all — they identify staff by a short code instead — so there is nothing for Connect to send from, and it falls back to a no-reply address with the Reply-To left blank for you to fill in.

To fix it, give that teammate a Send As identity — a shared sender identity with a real display name and reply address. Their emails will then send under that identity instead.