nano /etc/dovecot/sieve-after/spam-to-folder.sieve
require ["fileinto","mailbox"];

if header :contains "X-Spam-Flag" "YES" {
fileinto :create "Junk";
stop;
}
if header :contains "X-Spam_bar" "+" {
fileinto :create "Junk";
stop;
}
if header :contains "X-Spam_bar" "++" {
fileinto :create "Junk";
stop;
}
if header :contains "X-Spam_bar" "+++" {
fileinto :create "Junk";
stop;
}
if header :contains "X-Spam_bar" "++++" {
fileinto :create "Junk";
stop;
}
if header :contains "X-Spam_bar" "+++++" {
fileinto :create "Junk";
stop;
}

chown -R root:dovecot /etc/dovecot/sieve-after
sievec /etc/dovecot/sieve-after/spam-to-folder.sieve