A lot of our campaigns target thousands of users in one bucket. There are teams with as little as 3 users supporting these efforts. To have the ability to set up auto replies for a specific mailing list, would let the end-user know "We have received your email and our team will review your issue as soon as possible, for immediate action please contact X,Y,Z."
Thank you for your idea, we are planing this for a future release. Please follow this idea for updates!