Yes Matt, I agree with you. However, for some reason a customer is complaining that some people are receiving several copies (in one case up to 15 copies) with exactly the same content, when he/she sent just one mail.
I thought at the beginning it may be a problem with his mail client but after checking the logs I didn't see anything strange but those repeated lines. I now understand that those repeated logs are normal as the filter is re-injecting them into postfix. The only irregular thing I saw is that his/her mails are being marked as SPAM (but not rejected), which then are sent to quarantine. As far as I know, I have to manually "release" them from quarantine in order to be send, right? For now, I use those emails in quarantine to adjust the values of spamassassin until I can reach some comfortable setup in order to start blocking emails. Is there any other way I could analyze the "duplicated mails" problem? Thanks again.