Warn for blocking common domains

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

@@ -858,7 +858,7 @@ public class EntityRule {
         return cal;
     }
 
-    static EntityRule blockSender(Context context, EntityMessage message, EntityFolder junk, boolean block_domain, List<String> whitelist) throws JSONException {
+    static EntityRule blockSender(Context context, EntityMessage message, EntityFolder junk, boolean block_domain) throws JSONException {
         if (message.from == null || message.from.length == 0)
             return null;
 
@@ -873,17 +873,8 @@ public class EntityRule {
         if (block_domain) {
             int at = sender.indexOf('@');
             if (at > 0) {
-                boolean whitelisted = false;
-                String domain = UriHelper.getParentDomain(context, sender.substring(at + 1));
-                for (String d : whitelist)
-                    if (domain.matches(d)) {
-                        whitelisted = true;
-                        break;
-                    }
-                if (!whitelisted) {
-                    regex = true;
-                    sender = ".*@.*" + domain + ".*";
-                }
+                regex = true;
+                sender = ".*@.*" + sender.substring(at + 1) + ".*";
             }
         }
 

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

@@ -25,6 +25,8 @@ import android.content.Context;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.SharedPreferences;
+import android.content.res.ColorStateList;
+import android.os.Build;
 import android.os.Bundle;
 import android.text.TextUtils;
 import android.view.LayoutInflater;
@@ -48,6 +50,10 @@ import androidx.preference.PreferenceManager;
 import org.json.JSONObject;
 
 import java.util.List;
+import java.util.Locale;
+
+import javax.mail.Address;
+import javax.mail.internet.InternetAddress;
 
 public class FragmentDialogJunk extends FragmentDialogBase {
     @NonNull
@@ -264,6 +270,35 @@ public class FragmentDialogJunk extends FragmentDialogBase {
             }
         });
 
+        try {
+            boolean common = false;
+            Address[] froms = InternetAddress.parseHeader(from, false);
+            String email = (froms.length == 0 ? null : ((InternetAddress) froms[0]).getAddress());
+            int at = (email == null ? -1 : email.indexOf('@'));
+            String domain = (at > 0 ? email.substring(at + 1).toLowerCase(Locale.ROOT) : null);
+
+            if (domain != null) {
+                List<String> domains = EmailProvider.getDomainNames(context);
+                for (String d : domains)
+                    if (domain.matches(d)) {
+                        common = true;
+                        break;
+                    }
+            }
+
+            if (common) {
+                int dp6 = Helper.dp2pixels(context, 6);
+                int colorWarning = Helper.resolveColor(context, R.attr.colorWarning);
+                cbBlockDomain.setTextColor(colorWarning);
+                cbBlockDomain.setCompoundDrawablesRelativeWithIntrinsicBounds(0, 0, R.drawable.twotone_warning_24, 0);
+                cbBlockDomain.setCompoundDrawablePadding(dp6);
+                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)
+                    cbBlockDomain.setCompoundDrawableTintList(ColorStateList.valueOf(colorWarning));
+            }
+        } catch (Throwable ex) {
+            Log.e(ex);
+        }
+
         // Initialize
         tvMessage.setText(inJunk
                 ? getString(R.string.title_folder_junk)

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

@@ -8003,7 +8003,7 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
                                 EntityContact.TYPE_JUNK, message.received);
 
                     if (block_domain) {
-                        EntityRule rule = EntityRule.blockSender(context, message, junk, block_domain, whitelist);
+                        EntityRule rule = EntityRule.blockSender(context, message, junk, block_domain);
                         if (rule != null) {
                             if (message.folder.equals(junk.id)) {
                                 EntityFolder inbox = db.folder().getFolderByType(message.account, EntityFolder.INBOX);

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

@@ -252,7 +252,6 @@ public class ServiceUI extends IntentService {
     private void onJunk(long id) throws JSONException {
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
         boolean block_sender = prefs.getBoolean("notify_block_sender", false);
-        List<String> whitelist = EmailProvider.getDomainNames(this);
 
         DB db = DB.getInstance(this);
         try {
@@ -269,7 +268,7 @@ public class ServiceUI extends IntentService {
             EntityOperation.queue(this, message, EntityOperation.MOVE, junk.id);
 
             if (block_sender) {
-                EntityRule rule = EntityRule.blockSender(this, message, junk, false, whitelist);
+                EntityRule rule = EntityRule.blockSender(this, message, junk, false);
                 if (rule != null)
                     rule.id = db.rule().insertRule(rule);
             }