Spamsieve is working fine; confirmed with Michael Tsai based on my logs from Spamsieve . Nonetheless, unless i leave Mail.app open along with Airmail, Airmail generally does not move emails correctly identified by Spamsieve as spam to my Junk folder. They're not even listed in my Airmail operations log. Looking at the Spamsieve forum, this had been reported quite some time ago, but clearly has not been fixed.