dovecot: use rspamd X-Spamd-Result percentage to evaluate spam

- configures dovecot to use the spamtest sieve plugins
- configures sieve to read the score from X-Spamd-Result: headers
- before.sieve applies the ${spam_threshold} to the spamtest percentage
- freeposte.db stores a percentage for ${spam_threshold}
- migrate freeposte.db spam_threshold from X/15 to percentages

the filter investigates the overall ratio of the `rspamd` header
`X-Spamd-Result` that looks something like this:

X-Spamd-Result: default: True [12.36 / 15.00]
 RBL_SPAMHAUS_XBL(4.00)[]
 BAYES_SPAM(3.06)[92.67%]
 RBL_SPAMHAUS_XBL_ANY(4.00)[]
 ONCE_RECEIVED_STRICT(4.00)[]
 HFILTER_HELO_BAREIP(3.00)[]
 RBL_SORBS_DUL(2.00)[]
 HFILTER_HOSTNAME_UNKNOWN(2.50)[]
 RBL_SPAMHAUS_PBL(2.00)[]
 RBL_SORBS_RECENT(1.50)[]
 MIME_UNKNOWN(0.10)[application/x-rar-compressed]
 RDNS_NONE(1.00)[]
 RBL_SORBS(0.00)[]
 R_SPF_NEUTRAL(0.00)[?all]
 ONCE_RECEIVED(0.10)[]
 RBL_SEM(1.00)[]
 MIME_HTML_ONLY(0.20)[]
 RBL_UCEPROTECT_LEVEL1(1.00)[]
 MIME_GOOD(-0.10)[multipart/mixed]

the sieve `spamtest :percent :value` in this case would be
   100*12.36/15 = 82.4%
master
Christoph Rissner 8 years ago
parent 79adbbb76c
commit b9de28e910

@ -143,7 +143,7 @@ class User(Email):
# Settings
displayed_name = db.Column(db.String(160), nullable=False, default="")
spam_enabled = db.Column(db.Boolean(), nullable=False, default=True)
spam_threshold = db.Column(db.Numeric(), nullable=False, default=10.0)
spam_threshold = db.Column(db.Numeric(), nullable=False, default=80.0)
# Flask-login attributes
is_authenticated = True

@ -13,8 +13,8 @@ User settings
{{ form.hidden_tag() }}
{{ macros.form_field(form.displayed_name) }}
{{ macros.form_field(form.spam_enabled) }}
{{ macros.form_field(form.spam_threshold, step=1, max=15,
prepend='<span class="input-group-addon"><span id="threshold">'+(form.spam_threshold.data).__int__().__str__()+'</span>&nbsp;/&nbsp;15</span>',
{{ macros.form_field(form.spam_threshold, step=1, max=100,
prepend='<span class="input-group-addon"><span id="threshold">'+(form.spam_threshold.data).__int__().__str__()+'</span>&nbsp;/&nbsp;100</span>',
oninput='$("#threshold").text(this.value);') }}
{{ macros.form_field(form.submit) }}
</form>

@ -0,0 +1,37 @@
"""spam_threshold in percent
Revision ID: 27ae2f102682
Revises: dc8c25cf5b98
Create Date: 2016-09-30 08:06:15.025190
"""
# revision identifiers, used by Alembic.
revision = '27ae2f102682'
down_revision = 'dc8c25cf5b98'
from alembic import op
import sqlalchemy as sa
from freeposte.admin.models import User
from freeposte import db
def upgrade():
# spam_threshold is a X/15 based value, we're converting it to percent.
for user in User.query.all():
user.spam_threshold = int(100. * float(user.spam_threshold or 0.) / 15.)
db.session.commit()
# set default to 80%
with op.batch_alter_table('user') as batch:
batch.alter_column('spam_threshold', default=80.)
def downgrade():
# spam_threshold is a X/15 based value, we're converting it from percent.
for user in User.query.all():
user.spam_threshold = int(15. * float(user.spam_threshold or 0.) / 100.)
db.session.commit()
# set default to 10/15
with op.batch_alter_table('user') as batch:
batch.alter_column('spam_threshold', default=10.)

@ -149,7 +149,7 @@ service managesieve-login {
plugin {
sieve_dir = ~/sieve
sieve_plugins = sieve_extdata
sieve_extensions = +vnd.dovecot.extdata
sieve_extensions = +vnd.dovecot.extdata +spamtest +spamtestplus
sieve_before = /var/lib/dovecot/before.sieve
sieve_default = /var/lib/dovecot/default.sieve
sieve_after = /var/lib/dovecot/after.sieve
@ -162,8 +162,13 @@ plugin {
antispam_mail_spam = learn_spam
antispam_mail_notspam = learn_ham
antispam_mail_sendmail_args = -h;antispam:11334;-P;q1
}
# extract spam score from
# X-Spam-Result: .... [<value> / <max_value] ...
sieve_spamtest_status_type = score
sieve_spamtest_status_header = X-Spamd-Result: .*\[(-?[[:digit:]]+\.[[:digit:]]+) .*\]
sieve_spamtest_max_header = X-Spamd-Result: .*\[.* ([[:digit:]]+\.[[:digit:]]+)\]
}
###############
# Filtering
###############

@ -8,16 +8,14 @@ require "regex";
require "relational";
require "comparator-i;ascii-numeric";
require "vnd.dovecot.extdata";
require "spamtestplus";
if allof (string :is "${extdata.spam_enabled}" "1",
not header :matches "X-Spam-Status" "* score=-*",
header :matches "X-Spam-Status" "* score=*")
spamtest :percent :value "gt" :comparator "i;ascii-numeric" "${extdata.spam_threshold}")
{
if string :value "ge" :comparator "i;ascii-numeric" "${2}" "${extdata.spam_threshold}" {
setflag "\\seen";
fileinto :create "Junk";
stop;
}
}
if string :is "${extdata.reply_enabled}" "1" {

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