Hi there, I recently helped a client setup a public folder (in Exchange 2003) to receive messages to their jobs@ e-mail address that is published in job postings. A few months later I was approached about setting up an automatic response saying "Thank you for your interest, blah blah blah blah blah". I configured this a few weeks ago and everything was fine. Until this past weekend. On Sunday night a piece of spam hit the public folder that generated the expected auto response. Problem is, the address it went out to generated an undeliverable message which came back to the public folder's address. The public folder then responded "Thank you", and so began the endless loop. By Monday morning there were over 13,000 undeliverable messages in the jobs folder. I quickly blocked the remote server's IP address on the Exchange server as a temporary measure, but that's not going to prevent this issue from anywhere else. I've searched for the ability to set the auto response to only respond to a given e-mail address once, but no such luck. So .. does anyone know if there's such a setting? Or any thought on how this might be accomplished? I'm hoping there's a way to control the number of automaticresponses a public folder will send to any given e-mail address. Otherwise the only other this I can think of is creating a couple of rules to look for the words "undeliverable" or "failure" in the subject line and deleting them before the autoresponse fires. Thanks, Neil

Clarify: Auto response-enabled public folder happens endless loop with external address When you use the auto response rule, each auto response is a new message and therefore will not be detected as a loop by Exchange. The only workaround I could suggest would be to somehow make use of the Out of Office [OOF] assistant for these users. The OOF message logic is built in to not send more than one response per sender. Of course, that would require that all Exchange servers in the organization be allowed to send OOF messages to the internet and that can considered be a security issue If you want to make use of OOF feature for this public folder, use the steps below: 1. Set public folder to be a moderated public folder [KB 182904] 2. You can create a new mail-enabled user account [So call it AutoResponser] that enable OOF feature for auto response Notes: Then all mails that send to public folder will be forward to AutoResponser. OOF feature will make AutoResponser to reply senders mail