[otrs] a couple of questions

hello there, I'm new to this list - apologies if these questions have already been covered. it seems that OTRS decides to send no auto reply on certain addresses. the logged action looks like this: " OTRS-PM3-80 Sent no 'auto reply' for Ticket [1234567890] (joe dough ) because the sender don't want a auto-response (e. g. loop or precedence header) " how can I switch off this behaviour? the second question I have is about the auto responses. in fact I would like to send an email to the customer once his ticket has been closed. how can I do that? thanks in advance, marc --