Skip classifying filtered messages

app/src/main/java/eu/faircode/email/Core.java

@@ -3786,12 +3786,16 @@ class Core {
 
         DB db = DB.getInstance(context);
         try {
+            boolean executed = false;
             for (EntityRule rule : rules)
                 if (rule.matches(context, message, imessage)) {
                     rule.execute(context, message);
+                    executed = true;
                     if (rule.stop)
                         break;
                 }
+            if (executed)
+                EntityOperation.queue(context, message, EntityOperation.KEYWORD, MessageHelper.FLAG_FILTERED, true);
         } catch (Throwable ex) {
             Log.e(ex);
             db.message().setMessageError(message.id, Log.formatThrowable(ex));

app/src/main/java/eu/faircode/email/MessageClassifier.java

@@ -104,6 +104,7 @@ public class MessageClassifier {
                     !classified.equals(folder.name) &&
                     !TextUtils.isEmpty(message.msgid) &&
                     !message.hasKeyword(MessageHelper.FLAG_CLASSIFIED) &&
+                    !message.hasKeyword(MessageHelper.FLAG_FILTERED) &&
                     !accountMsgIds.get(folder.account).contains(message.msgid) &&
                     !EntityFolder.JUNK.equals(folder.type)) {
                 boolean pro = ActivityBilling.isPro(context);

app/src/main/java/eu/faircode/email/MessageHelper.java

@@ -138,6 +138,7 @@ public class MessageHelper {
     static final String FLAG_FORWARDED = "$Forwarded";
     static final String FLAG_NOT_JUNK = "$NotJunk";
     static final String FLAG_CLASSIFIED = "$Classified";
+    static final String FLAG_FILTERED = "$Filtered";
 
     // https://www.iana.org/assignments/imap-jmap-keywords/imap-jmap-keywords.xhtml
     // Not black listed: Gmail $Phishing
@@ -145,6 +146,7 @@ public class MessageHelper {
             MessageHelper.FLAG_FORWARDED,
             MessageHelper.FLAG_NOT_JUNK,
             MessageHelper.FLAG_CLASSIFIED, // FairEmail
+            MessageHelper.FLAG_FILTERED, // FairEmail
             "$MDNSent", // https://tools.ietf.org/html/rfc3503
             "$SubmitPending",
             "$Submitted",