https://www.plesk.com/kb/support/high-cpu-usage-for-sa-learn-and-spamtrain-processes-in-a-server-with-plesk/
High CPU usage for "sa-learn" and "spamtrain" processes in a server with Plesk - Support Cases from...
Symptoms High CPU usage for sa-learn and spamtrain processes in the Plesk server. Cause Since the sa-learn script is used by spamassassin to learn the specific...