Added option to turn off native ARC

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

@@ -227,6 +227,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
     private SwitchCompat swLogarithmicBackoff;
     private SwitchCompat swExactAlarms;
     private SwitchCompat swNativeDkim;
+    private SwitchCompat swNativeArc;
     private SwitchCompat swInfra;
     private SwitchCompat swDupMsgId;
     private EditText etKeywords;
@@ -287,7 +288,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
             "auth_plain", "auth_login", "auth_ntlm", "auth_sasl", "auth_apop", "use_top",
             "keep_alive_poll", "empty_pool", "idle_done", "fast_fetch",
             "max_backoff_power", "logarithmic_backoff",
-            "exact_alarms", "native_dkim", "infra", "dkim_verify", "dup_msgids", "global_keywords", "test_iab"
+            "exact_alarms", "native_dkim", "native_arc", "infra", "dkim_verify", "dup_msgids", "global_keywords", "test_iab"
     };
 
     private final static String[] RESET_QUESTIONS = new String[]{
@@ -462,6 +463,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
         swLogarithmicBackoff = view.findViewById(R.id.swLogarithmicBackoff);
         swExactAlarms = view.findViewById(R.id.swExactAlarms);
         swNativeDkim = view.findViewById(R.id.swNativeDkim);
+        swNativeArc = view.findViewById(R.id.swNativeArc);
         swInfra = view.findViewById(R.id.swInfra);
         swDupMsgId = view.findViewById(R.id.swDupMsgId);
         etKeywords = view.findViewById(R.id.etKeywords);
@@ -1701,6 +1703,15 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
             @Override
             public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
                 prefs.edit().putBoolean("native_dkim", checked).apply();
+                swNativeArc.setEnabled(checked && swNativeDkim.isEnabled());
+            }
+        });
+
+        swNativeArc.setEnabled(!BuildConfig.PLAY_STORE_RELEASE);
+        swNativeArc.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
+                prefs.edit().putBoolean("native_arc", checked).apply();
             }
         });
 
@@ -2425,6 +2436,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
         swLogarithmicBackoff.setChecked(prefs.getBoolean("logarithmic_backoff", true));
         swExactAlarms.setChecked(prefs.getBoolean("exact_alarms", true));
         swNativeDkim.setChecked(prefs.getBoolean("native_dkim", false));
+        swNativeArc.setChecked(prefs.getBoolean("native_arc", true));
         swInfra.setChecked(prefs.getBoolean("infra", false));
         swDupMsgId.setChecked(prefs.getBoolean("dup_msgids", false));
         etKeywords.setText(prefs.getString("global_keywords", null));

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

@@ -2028,7 +2028,9 @@ public class MessageHelper {
 
             Log.i("DKIM signers=" + TextUtils.join(",", signers));
 
-            if (signers.size() == 0) {
+            SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+            boolean native_arc = prefs.getBoolean("native_arc", true);
+            if (signers.size() == 0 && native_arc) {
                 // https://datatracker.ietf.org/doc/html/rfc8617#section-5.2
                 boolean ok = true; // Until it is not
                 Map<Integer, String> as = new HashMap<>();
@@ -2065,6 +2067,8 @@ public class MessageHelper {
                     if (!ok)
                         break;
                 }
+
+                ok = (ok && as.size() > 0);
                 Log.i("ARC as=" + as.size() + " aar=" + aar.size() + " ams=" + ams.size() + " ok=" + ok);
 
                 if (ok &&

app/src/main/res/layout/fragment_options_misc.xml

@@ -1863,6 +1863,18 @@
                     app:layout_constraintStart_toStartOf="parent"
                     app:layout_constraintTop_toBottomOf="@id/swNativeDkim" />
 
+                <androidx.appcompat.widget.SwitchCompat
+                    android:id="@+id/swNativeArc"
+                    android:layout_width="0dp"
+                    android:layout_height="wrap_content"
+                    android:layout_marginStart="12dp"
+                    android:layout_marginTop="12dp"
+                    android:text="@string/title_advanced_native_dkim"
+                    app:layout_constraintEnd_toEndOf="parent"
+                    app:layout_constraintStart_toStartOf="parent"
+                    app:layout_constraintTop_toBottomOf="@id/tvNativeDkimHint"
+                    app:switchPadding="12dp" />
+
                 <androidx.appcompat.widget.SwitchCompat
                     android:id="@+id/swInfra"
                     android:layout_width="0dp"
@@ -1871,7 +1883,7 @@
                     android:text="@string/title_advanced_infra"
                     app:layout_constraintEnd_toEndOf="parent"
                     app:layout_constraintStart_toStartOf="parent"
-                    app:layout_constraintTop_toBottomOf="@id/tvNativeDkimHint"
+                    app:layout_constraintTop_toBottomOf="@id/swNativeArc"
                     app:switchPadding="12dp" />
 
                 <androidx.constraintlayout.helper.widget.Flow