Date: 2019sep25 Product: SpamAssassin Q. SpamAssassin: why aren't some messages processed A. By default messages over 500KB are skipped. If you're using Postfix you can specify the --max-size like this In file /etc/postfix/master.cf

spamassassin unix - n n - - pipe user=spamd argv=/usr/bin/spamc --max-size=1000000 -f -e /usr/sbin/sendmail -oi -f ${sender} ${recipient}