It's hard to judge but for me Fastmail seems to be pretty great at detecting spam, at least it always ends up in my Spam folder. False positives are pretty regular, so far never actual human written emails though, only newsletters, but still. Overall for me a set and happily forget kind of service. Support is decent too.

My company used to be on Fastmail. Spam was definitely a problem. It's not EU based either if that matters (although the relevant servers may be).