I have solved this issue. The problem was that those particular mails have been forwarded (bounced) by our own system from another of our e-mail address. That's why our own domain name was also listed in the mail header. And our domain was white-listed. Now I have removed our own domain from the whitelist.

Hi,

We are receiving spam from certain sender addresses regularly. That's why we took over those addresses in our blacklist. This works properly during the last months. Now we experience that some of those mails are coming with the following flag already set:

X-AC-Weight: [####] (Whitelisted) -9999

X-CC-Diagnostic:
 

And that's why they are unfortunately not longer being sorted out.

Could I change any settings in Mercury so that the blacklist has higher priority than any whitelist state?

Cheers

Joerg