I get so many PMs from people who don't even care to search the forum that to be honest I stopped reading PMs... That's why I prefer public discussion, so also other people can benefit from answers and I don't have to repeat myself again and again (heck I still do it a lot

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As per your question - yes, proxies do add a lot to JunkMark score. I'd suggest setting the limit to 90 or 100 and see if it works fine and you don't get (much) spam.
I will add an option to not use proxies in JunkMark calculation, but probably not before October (busy writing my diploma...).