Dovecot 2.4 sieve for automatically filing rspamd spam into the Junk folder

spam-to-junk.sieve.j2

require ["fileinto", "mailbox", "spamtest", "spamtestplus", "relational", "comparator-i;ascii-numeric"];

# See dovecot.conf for matching configuration: https://gist.github.com/dmckeone/7cdf170624d77c4ddcdce1721c6f760e
# This configuration is intended to be used with Jinja2, so all variables look like: {{ variable }}

# Must install spamtest & spamtestplus and normalize spam headers in dovecot.conf: https://doc.dovecot.org/main/core/config/sieve/extensions/spamtest_virustest.html
# :percent normalizes the rspamd score ratio to a percent, so "X-Spamd-Result: default: False [12.00 / 15.00]" would be 12 / 15 = 0.8 or 80%.
#
# Don't create INBOX/Junk; only sort mail if it already exists
if mailboxexists "INBOX/Junk" {
  if spamtest :percent :value "eq" :comparator "i;ascii-numeric" "100" {
    # spamtest returned 100% (spam)
    fileinto :create "INBOX/Junk";
    stop;
  }
}