[otrs] Auto replies not sent

Hello, I'm having a problem with the auto replies in that they aren't being sent. The logs indicate that no auto reply was sent because the "*sender doesn't want a auto-response (e.g. loop or precedence header)".* Test messages sent to support@ourdomain are forwarded to otrs@ourdomain, where they are picked up by otrs and now have the "precedence: list" header. Is this the root of the problem and if so is there a way to force the sending of the replies? Cheers, SRG