I am very pleased with Mail’s ability to handle spam. I’ve got three different accounts of various ages pointed at a single account that is used by Mail. This meta-account receives a huge amount of spam, most of which is filtered nicely into nothingness.
One strain of spam that has been getting through for the past few weeks has been a slew of mortgage, loan, and financial crap. Getting frustrated, I looked at the Junk Mail pref and looked at what knobs and dials were available. Turns out there is one which immediately handled the problem. Out of the box, Mail exempts messages messages addressed using my full name and this was how this class of spam was getting through.
I’ve been running with the modified rule set for three days now and it’s nabbed everything with only one moderate false positive.
Your mileage may vary.