Under Mavericks using Apple Mail and SpamSieve, Mail would only make a sound when genuine mail arrived, but since upgrading to El Capitan and SS 2.9.24, Mail makes a sound even when spam arrives. Although not a serious issue it was useful to know when I heard a sound I had actual mail because spam was ignored. It means from my home office, I check my mail more often only to find spam. Have I missed something in settings of either?
I don’t think Mail’s behavior changed between those OS versions. Perhaps your settings did. Please see this page.
A million thanks Michael. I don’t know what I would do without your fantastic app. Since my email address was hacked and has been sold on so many times I get tons. I even have the server filters set to high. Your SpamSieve is the last defense and it just works so well.