Added option to send NIL ID

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

@@ -609,10 +609,14 @@ public class EmailService implements AutoCloseable {
             IMAPStore istore = (IMAPStore) getStore();
             if (istore.hasCapability("ID"))
                 try {
+                    SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+                    boolean client_id = prefs.getBoolean("client_id", true);
+
                     Map<String, String> id = new LinkedHashMap<>();
                     id.put("name", context.getString(R.string.app_name));
                     id.put("version", BuildConfig.VERSION_NAME);
-                    Map<String, String> sid = istore.id(id);
+
+                    Map<String, String> sid = istore.id(client_id ? id : null);
                     if (sid != null) {
                         Map<String, String> crumb = new HashMap<>();
                         for (String key : sid.keySet()) {

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

@@ -69,6 +69,8 @@ public class FragmentOptionsPrivacy extends FragmentBase implements SharedPrefer
     private Button btnPin;
     private Button btnBiometrics;
     private Spinner spBiometricsTimeout;
+    private SwitchCompat swClientId;
+    private TextView tvClientId;
     private SwitchCompat swDisplayHidden;
     private SwitchCompat swIncognitoKeyboard;
     private ImageButton ibIncognitoKeyboard;
@@ -90,7 +92,7 @@ public class FragmentOptionsPrivacy extends FragmentBase implements SharedPrefer
             "confirm_links", "browse_links", "confirm_images", "confirm_html",
             "disable_tracking", "hide_timezone",
             "pin", "biometrics", "biometrics_timeout",
-            "display_hidden", "incognito_keyboard", "secure",
+            "client_id", "display_hidden", "incognito_keyboard", "secure",
             "generic_ua", "safe_browsing",
             "disconnect_auto_update", "disconnect_links", "disconnect_images"
     };
@@ -114,6 +116,8 @@ public class FragmentOptionsPrivacy extends FragmentBase implements SharedPrefer
         btnPin = view.findViewById(R.id.btnPin);
         btnBiometrics = view.findViewById(R.id.btnBiometrics);
         spBiometricsTimeout = view.findViewById(R.id.spBiometricsTimeout);
+        swClientId = view.findViewById(R.id.swClientId);
+        tvClientId = view.findViewById(R.id.tvClientId);
         swDisplayHidden = view.findViewById(R.id.swDisplayHidden);
         swIncognitoKeyboard = view.findViewById(R.id.swIncognitoKeyboard);
         ibIncognitoKeyboard = view.findViewById(R.id.ibIncognitoKeyboard);
@@ -232,6 +236,14 @@ public class FragmentOptionsPrivacy extends FragmentBase implements SharedPrefer
             }
         });
 
+        swClientId.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
+                prefs.edit().putBoolean("client_id", checked).apply();
+                ServiceSynchronize.reload(compoundButton.getContext(), null, false, "id");
+            }
+        });
+
         swDisplayHidden.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
             @Override
             public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
@@ -354,6 +366,8 @@ public class FragmentOptionsPrivacy extends FragmentBase implements SharedPrefer
                     : R.color.lightColorBackground_cards));
         }
 
+        tvClientId.setText(getString(R.string.app_name) + " " + BuildConfig.VERSION_NAME);
+
         PreferenceManager.getDefaultSharedPreferences(getContext()).registerOnSharedPreferenceChangeListener(this);
 
         return view;
@@ -415,6 +429,7 @@ public class FragmentOptionsPrivacy extends FragmentBase implements SharedPrefer
                 break;
             }
 
+        swClientId.setChecked(prefs.getBoolean("client_id", true));
         swDisplayHidden.setChecked(prefs.getBoolean("display_hidden", false));
         swIncognitoKeyboard.setChecked(prefs.getBoolean("incognito_keyboard", false));
         swSecure.setChecked(prefs.getBoolean("secure", false));

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

@@ -273,6 +273,30 @@
                     app:layout_constraintStart_toStartOf="parent"
                     app:layout_constraintTop_toTopOf="parent" />
 
+                <androidx.appcompat.widget.SwitchCompat
+                    android:id="@+id/swClientId"
+                    android:layout_width="0dp"
+                    android:layout_height="wrap_content"
+                    android:layout_marginTop="12dp"
+                    android:checked="true"
+                    android:text="@string/title_advanced_client_id"
+                    app:layout_constraintEnd_toEndOf="parent"
+                    app:layout_constraintStart_toStartOf="parent"
+                    app:layout_constraintTop_toBottomOf="@id/tvAdvanced"
+                    app:switchPadding="12dp" />
+
+                <eu.faircode.email.FixedTextView
+                    android:id="@+id/tvClientId"
+                    android:layout_width="0dp"
+                    android:layout_height="wrap_content"
+                    android:layout_marginEnd="48dp"
+                    android:text="FairEmail 1.2345"
+                    android:textAppearance="@style/TextAppearance.AppCompat.Small"
+                    android:textStyle="italic"
+                    app:layout_constraintEnd_toEndOf="parent"
+                    app:layout_constraintStart_toStartOf="parent"
+                    app:layout_constraintTop_toBottomOf="@id/swClientId" />
+
                 <androidx.appcompat.widget.SwitchCompat
                     android:id="@+id/swDisplayHidden"
                     android:layout_width="0dp"
@@ -281,7 +305,7 @@
                     android:text="@string/title_advanced_display_hidden"
                     app:layout_constraintEnd_toEndOf="parent"
                     app:layout_constraintStart_toStartOf="parent"
-                    app:layout_constraintTop_toBottomOf="@id/tvAdvanced"
+                    app:layout_constraintTop_toBottomOf="@id/tvClientId"
                     app:switchPadding="12dp" />
 
                 <eu.faircode.email.FixedTextView

app/src/main/res/values/strings.xml

@@ -504,6 +504,7 @@
     <string name="title_advanced_confirm_html">Show reformatted messages by default</string>
     <string name="title_advanced_tracking">Attempt to recognize and disable tracking images</string>
     <string name="title_advanced_hide_timezone">Send messages without timezone data</string>
+    <string name="title_advanced_client_id">Send app name and version to email server</string>
     <string name="title_advanced_display_hidden">Display hidden message texts</string>
     <string name="title_advanced_incognito_keyboard">Use incognito keyboard (Android 8+)</string>
     <string name="title_advanced_secure">Hide from recent apps screen and prevent taking screenshots</string>