v0.3.10

resources/config/sieve/bayes_classify.sieve

@@ -1,5 +1,12 @@
 if eval "!t.SPAM_TRAP && !t.TRUSTED_REPLY" {
-    let "bayes_result" "bayes_classify('spamdb/token-lookup', body_and_subject)";
+
+    # Classification parameters
+    # min_token_hits: 2
+    # min_tokens: 11
+    # min_prob_strength: 0.05
+    # min_learns: 200
+
+    let "bayes_result" "bayes_classify('spamdb/token-lookup', body_and_subject, [2, 11, 0.05, 200])";
     if eval "!is_empty(bayes_result)" {
         if eval "bayes_result > 0.7" {
             let "t.BAYES_SPAM" "1";

resources/config/sieve/config.sieve

@@ -0,0 +1,33 @@
+# Whether to add an X-Spam-Status header
+let "ADD_HEADER_SPAM" "true";
+
+# Whether to add an X-Spam-Result header
+let "ADD_HEADER_SPAM_RESULT" "true";
+
+# Whether message replies from authenticated users should be learned as ham
+let "AUTOLEARN_REPLIES_HAM" "true";
+
+# Whether the bayes classifier should be trained automatically
+let "AUTOLEARN_ENABLE" "true";
+
+# When to learn ham (score >= threshold)
+let "AUTOLEARN_HAM_THRESHOLD" "-0.5";
+
+# When to learn spam (score <= threshold)
+let "AUTOLEARN_SPAM_THRESHOLD" "6.0";
+
+# Keep difference for spam/ham learns for at least this value
+let "AUTOLEARN_SPAM_HAM_BALANCE" "0.9";
+
+# If ADD_HEADER_SPAM is enabled, mark as SPAM messages with a score above this threshold
+let "SCORE_SPAM_THRESHOLD" "5.0";
+
+# Discard messages with a score above this threshold
+let "SCORE_DISCARD_THRESHOLD" "0";
+
+# Reject messages with a score above this threshold
+let "SCORE_REJECT_THRESHOLD" "0";
+
+# Directory name to use for local domain lookups
+let "DOMAIN_DIRECTORY" "'default'";
+

resources/config/sieve/epilogue.sieve

@@ -0,0 +1,58 @@
+
+# Train the bayes classifier automatically
+if eval "AUTOLEARN_ENABLE && (score >= AUTOLEARN_SPAM_THRESHOLD || score <= AUTOLEARN_HAM_THRESHOLD)" {
+    let "is_spam" "score >= AUTOLEARN_SPAM_THRESHOLD";
+    eval "bayes_is_balanced('spamdb/token-lookup', is_spam, AUTOLEARN_SPAM_HAM_BALANCE) && 
+          bayes_train('spamdb/token-insert', body_and_subject, is_spam)";
+}
+
+add balance
+
+# Iterate over tags
+let "tags" "var_names()";
+let "i" "count(tags)";
+let "spam_result" "";
+while "i > 0" {
+    let "i" "i - 1";
+    let "tag" "tags[i]";
+    let "tag_score" "map('spam/scores', tag)";
+
+    if eval "is_number(tag_score)" {
+        let "score" "score + tag_score";
+        if eval "ADD_HEADER_SPAM_RESULT" {
+            if eval "!is_empty(spam_result)" {
+                let "spam_result" "spam_result + ',\r\n\t' + tag + ' (' + tag_score + ')'";
+            } else {
+                let "spam_result" "spam_result + tag + ' (' + tag_score + ')'";
+            }
+        }
+    } elsif eval "tag_score == 'reject' {
+        let "SCORE_REJECT_THRESHOLD" "1";
+        let "score" "2";
+        break;
+    } else if eval "tag_score == 'discard'" {
+        discard;
+        stop;
+    }
+}
+
+# Process score actions
+if "SCORE_REJECT_THRESHOLD && score >= SCORE_REJECT_THRESHOLD" {
+    reject "Your message has been rejected because it has an excessive spam score. If you feel this is an error, please contact the postmaster.";
+    stop;
+} else if "SCORE_DISCARD_THRESHOLD && score >= SCORE_DISCARD_THRESHOLD" {
+    discard;
+    stop;
+} else if "ADD_HEADER_SPAM" {
+    let "spam_status" "";
+    if eval "score >= SCORE_SPAM_THRESHOLD" {
+        let "spam_status" "'Yes, score=' + score";
+    } else {
+        let "spam_status" "'No, score=' + score";
+    }
+    eval "add-header('X-Spam-Status', spam_status)";
+    if eval "!is_empty(spam_result)" {
+        eval "add-header('X-Spam-Result', spam_result)";
+    }
+}
+

resources/config/sieve/greylist.sieve

@@ -0,0 +1,9 @@
+
+set "triplet" "${env.remote_ip}.${envelope.from}.${envelope.to}";
+
+if eval "!lookup('spamdb/id-lookup', triplet)" {
+    # Greylist sender for 30 days
+    eval "lookup_map('spamdb/id-insert', [triplet, 2592000])";
+    reject "422 4.2.2 Greylisted, please try again in a few moments.";
+    stop;
+}

resources/config/sieve/mime.sieve

@@ -9,6 +9,11 @@ if eval "!header.mime-version.exists" {
 let "has_text_part" "0";
 let "is_encrypted" "0";
 
+if eval "header.Content-Type.exists && !header.Content-Disposition:Content-Transfer-Encoding:MIME-Version.exists && !eq_ignore_case(header.Content-Type, 'text/plain')" {
+    # Only Content-Type header without other MIME headers
+    let "t.MIME_HEADER_CTYPE_ONLY" "1";
+}
+
 foreverypart {
     let "content_type" "to_lowercase(header.content-type)";
     let "type" "to_lowercase(header.content-type.type)";
@@ -138,13 +143,8 @@ foreverypart {
         }
     }
 
-    if eval "is_empty(type)" {
-        if eval "header.content-type.exists" {
-            let "t.BROKEN_CONTENT_TYPE" "1";
-        }
-    } elsif eval "!header.Content-Disposition:Content-Transfer-Encoding:MIME-Version.exists && (type != 'text' || subtype != 'plain')" {
-        # Only Content-Type header without other MIME headers
-        let "t.MIME_HEADER_CTYPE_ONLY" "1";
+    if eval "is_empty(type) && header.content-type.exists" {
+        let "t.BROKEN_CONTENT_TYPE" "1";
     }
 
     if eval "part_is_attachment" {

resources/config/sieve/prelude.sieve

@@ -38,3 +38,6 @@ let "envfrom_domain_sld" "domain_part(envfrom_domain, 'sld')";
 
 # Obtain HELO domain SLD
 let "helo_domain_sld" "domain_part(env.helo_domain, 'sld')";
+
+# Create score variable
+let "score" "0.0";

resources/config/sieve/rbl.sieve

@@ -171,7 +171,8 @@ while "i < domains_len" {
     let "domain" "domains[i]";
     let "i" "i + 1";
 
-    if eval "!contains(domain, '.') || is_ip_addr(domain)" {
+    # Skip invalid and local domain names
+    if eval "!contains(domain, '.') || is_ip_addr(domain) || is_local_domain(DOMAIN_DIRECTORY, domain_part(domain, 'sld'))" {
         continue;
     }
 
@@ -286,7 +287,8 @@ while "i < emails_len" {
     let "email" "emails[i]";
     let "i" "i + 1";
 
-    if eval "!contains(email, '@')" {
+    # Skip invalid and local e-mail addresses
+    if eval "!contains(email, '@') || is_local_domain(DOMAIN_DIRECTORY, domain_part(email_part(email, 'domain'), 'sld'))" {
         continue;
     }
 
@@ -319,6 +321,11 @@ while "i < urls_len" {
         break;
     }
 
+    # Skip URLs pointing to local domains
+    if eval "is_local_domain(DOMAIN_DIRECTORY, domain_part(uri_part(url, 'host'), 'sld'))" {
+        continue;
+    }
+
     # Query SURBL HASHBL
     let "result" "rsplit_once(dns_query(hash(url, 'md5') + '.hashbl.surbl.org', 'ipv4')[0], '.')";
     if eval "starts_with(result[0], '127.0.')" {

resources/config/sieve/replies_out.sieve

@@ -3,9 +3,10 @@
 let "message_id" "header.Message-ID";
 
 if eval "!is_empty(message_id)" {
-    eval "lookup('spamdb/id-insert', message_id)";
+    # Store the message ID for 30 days
+    eval "lookup_map('spamdb/id-insert', [message_id, 2592000])";
 
-    if eval "lookup('spam/options', 'AUTOLEARN_REPLIES')" {
+    if eval "AUTOLEARN_ENABLE && AUTOLEARN_REPLIES_HAM && bayes_is_balanced('spamdb/token-lookup', false, AUTOLEARN_SPAM_HAM_BALANCE)" {
         eval "bayes_train('spamdb/token-insert', thread_name(header.subject) + ' ' + body.to_text, false)";
     }
 }

resources/config/sieve/spamtrap.sieve

@@ -1,6 +1,9 @@
 
 # Check if the message was sent to a spam trap address
-if eval "lookup('spam/trap-address', envelope.to)" {
-    eval "bayes_train('spamdb/token-insert', body_and_subject, true)";
+if eval "AUTOLEARN_ENABLE && lookup('spam/trap-address', envelope.to)" {
+    eval "bayes_is_balanced('spamdb/token-lookup', false, AUTOLEARN_SPAM_HAM_BALANCE) && bayes_train('spamdb/token-insert', body_and_subject, true)";
     let "t.SPAM_TRAP" "1";
+
+    # Disable autolearn so the classifier is not trained twice
+    let "AUTOLEARN_ENABLE" "0";
 }

resources/config/sieve/url.sieve

@@ -12,6 +12,12 @@ let "i" "count(urls)";
 while "i > 0" {
     let "i" "i - 1";
     let "url" "urls[i]";
+
+    # Skip non-URLs such as 'data:' and 'mailto:'
+    if eval "!contains(url, '://')" {
+        continue;
+    }
+
     let "host" "uri_part(url, 'host')";
 
     if eval "!is_empty(host)" {
@@ -20,6 +26,10 @@ while "i > 0" {
         let "host_lc" "to_lowercase(host)";
         let "host_sld" "domain_part(host_lc, 'sld')";
 
+        if eval "is_local_domain(DOMAIN_DIRECTORY, host_sld)" {
+            continue;
+        }
+
         if eval "!is_ip && 
                  (!t.REDIRECTOR_URL || !t.URL_REDIRECTOR_NESTED) && 
                  lookup('spam/redirectors', host_sld)" {