diff --git a/app/build.gradle b/app/build.gradle
index a90b721fab..4e8f3c537a 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -513,6 +513,7 @@ dependencies {
     def exif_version = "1.3.6"
     def biometric_version = "1.2.0-alpha05"
     def billingclient_version = "6.0.1"
+    def playservicesbase_version = "18.2.0";
     def javamail_version = "1.6.7"
     def jsoup_version = "1.16.2"
     def jsonpath_version = "2.8.0"
@@ -654,6 +655,12 @@ dependencies {
     largeImplementation "com.android.billingclient:billing:$billingclient_version"
     playImplementation "com.android.billingclient:billing:$billingclient_version"
 
+    // https://mvnrepository.com/artifact/com.google.android.gms/play-services-base
+    //githubImplementation "com.google.android.gms:play-services-basement:$playservicesbase_version"
+    //largeImplementation "com.google.android.gms:play-services-basement:$playservicesbase_version"
+    //playImplementation "com.google.android.gms:play-services-basement:$playservicesbase_version"
+    implementation "com.google.android.gms:play-services-basement:$playservicesbase_version"
+
     // https://developer.amazon.com/docs/in-app-purchasing/iap-get-started.html
     amazonImplementation files('lib/in-app-purchasing-2.0.76.jar')
 
diff --git a/app/src/amazon/AndroidManifest.xml b/app/src/amazon/AndroidManifest.xml
index 291dce703d..4393aac615 100644
--- a/app/src/amazon/AndroidManifest.xml
+++ b/app/src/amazon/AndroidManifest.xml
@@ -111,7 +111,7 @@
     </queries>
 
     <application
-        android:name=".ApplicationEx"
+        android:name=".ApplicationSecure"
         android:allowBackup="false"
         android:appCategory="productivity"
         android:dataExtractionRules="@xml/data_extraction_rules"
diff --git a/app/src/amazon/java/eu/faircode/email/ApplicationSecure.java b/app/src/amazon/java/eu/faircode/email/ApplicationSecure.java
new file mode 100644
index 0000000000..76c6fa32ba
--- /dev/null
+++ b/app/src/amazon/java/eu/faircode/email/ApplicationSecure.java
@@ -0,0 +1,26 @@
+package eu.faircode.email;
+
+import android.content.Intent;
+
+import com.google.android.gms.security.ProviderInstaller;
+
+public class ApplicationSecure extends ApplicationEx implements ProviderInstaller.ProviderInstallListener {
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        Log.i("Security provider check");
+        ProviderInstaller.installIfNeededAsync(this, this);
+    }
+
+    @Override
+    public void onProviderInstalled() {
+        Log.i("Security provider installed");
+    }
+
+    @Override
+    public void onProviderInstallFailed(int errorCode, Intent recoveryIntent) {
+        Log.i("Security provider install failed" +
+                " errorCode=" + errorCode +
+                " recoveryIntent=" + recoveryIntent);
+    }
+}
diff --git a/app/src/debug/AndroidManifest.xml b/app/src/debug/AndroidManifest.xml
index 675d0c2ffc..2ec8145bc7 100644
--- a/app/src/debug/AndroidManifest.xml
+++ b/app/src/debug/AndroidManifest.xml
@@ -119,7 +119,7 @@
     </queries>
 
     <application
-        android:name=".ApplicationEx"
+        android:name=".ApplicationSecure"
         android:allowBackup="false"
         android:appCategory="productivity"
         android:dataExtractionRules="@xml/data_extraction_rules"
diff --git a/app/src/fdroid/AndroidManifest.xml b/app/src/fdroid/AndroidManifest.xml
index 0f09dfdce9..13407efb08 100644
--- a/app/src/fdroid/AndroidManifest.xml
+++ b/app/src/fdroid/AndroidManifest.xml
@@ -118,7 +118,7 @@
     </queries>
 
     <application
-        android:name=".ApplicationEx"
+        android:name=".ApplicationSecure"
         android:allowBackup="false"
         android:appCategory="productivity"
         android:dataExtractionRules="@xml/data_extraction_rules"
diff --git a/app/src/fdroid/java/eu/faircode/email/ApplicationSecure.java b/app/src/fdroid/java/eu/faircode/email/ApplicationSecure.java
new file mode 100644
index 0000000000..76c6fa32ba
--- /dev/null
+++ b/app/src/fdroid/java/eu/faircode/email/ApplicationSecure.java
@@ -0,0 +1,26 @@
+package eu.faircode.email;
+
+import android.content.Intent;
+
+import com.google.android.gms.security.ProviderInstaller;
+
+public class ApplicationSecure extends ApplicationEx implements ProviderInstaller.ProviderInstallListener {
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        Log.i("Security provider check");
+        ProviderInstaller.installIfNeededAsync(this, this);
+    }
+
+    @Override
+    public void onProviderInstalled() {
+        Log.i("Security provider installed");
+    }
+
+    @Override
+    public void onProviderInstallFailed(int errorCode, Intent recoveryIntent) {
+        Log.i("Security provider install failed" +
+                " errorCode=" + errorCode +
+                " recoveryIntent=" + recoveryIntent);
+    }
+}
diff --git a/app/src/github/AndroidManifest.xml b/app/src/github/AndroidManifest.xml
index bce7e59cbf..8ebe1d9e6d 100644
--- a/app/src/github/AndroidManifest.xml
+++ b/app/src/github/AndroidManifest.xml
@@ -118,7 +118,7 @@
     </queries>
 
     <application
-        android:name=".ApplicationEx"
+        android:name=".ApplicationSecure"
         android:allowBackup="false"
         android:appCategory="productivity"
         android:dataExtractionRules="@xml/data_extraction_rules"
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 1e73a448dc..597cedb17c 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -111,7 +111,7 @@
     </queries>
 
     <application
-        android:name=".ApplicationEx"
+        android:name=".ApplicationSecure"
         android:allowBackup="false"
         android:appCategory="productivity"
         android:dataExtractionRules="@xml/data_extraction_rules"
diff --git a/app/src/main/java/eu/faircode/email/EmailService.java b/app/src/main/java/eu/faircode/email/EmailService.java
index 0a77115167..74f0651672 100644
--- a/app/src/main/java/eu/faircode/email/EmailService.java
+++ b/app/src/main/java/eu/faircode/email/EmailService.java
@@ -235,14 +235,14 @@ public class EmailService implements AutoCloseable {
         Log.i("Timeout=" + timeout);
         if (purpose == PURPOSE_SEARCH) {
             properties.put("mail." + protocol + ".connectiontimeout", Integer.toString(timeout));
-            properties.put("mail." + protocol + ".writetimeout", Integer.toString(SEARCH_TIMEOUT));
+            //properties.put("mail." + protocol + ".writetimeout", Integer.toString(SEARCH_TIMEOUT));
             properties.put("mail." + protocol + ".timeout", Integer.toString(SEARCH_TIMEOUT));
         } else {
             int factor = 2;
             if ("smtp".equals(protocol) || "smtps".equals(protocol))
                 factor *= 2;
             properties.put("mail." + protocol + ".connectiontimeout", Integer.toString(timeout));
-            properties.put("mail." + protocol + ".writetimeout", Integer.toString(timeout * factor));
+            //properties.put("mail." + protocol + ".writetimeout", Integer.toString(timeout * factor));
             properties.put("mail." + protocol + ".timeout", Integer.toString(timeout * factor));
         }
 
diff --git a/app/src/play/AndroidManifest.xml b/app/src/play/AndroidManifest.xml
index af2011ff14..c89be0936f 100644
--- a/app/src/play/AndroidManifest.xml
+++ b/app/src/play/AndroidManifest.xml
@@ -111,7 +111,7 @@
     </queries>
 
     <application
-        android:name=".ApplicationEx"
+        android:name=".ApplicationSecure"
         android:allowBackup="false"
         android:appCategory="productivity"
         android:dataExtractionRules="@xml/data_extraction_rules"
diff --git a/app/src/play/java/eu/faircode/email/ApplicationSecure.java b/app/src/play/java/eu/faircode/email/ApplicationSecure.java
new file mode 100644
index 0000000000..76c6fa32ba
--- /dev/null
+++ b/app/src/play/java/eu/faircode/email/ApplicationSecure.java
@@ -0,0 +1,26 @@
+package eu.faircode.email;
+
+import android.content.Intent;
+
+import com.google.android.gms.security.ProviderInstaller;
+
+public class ApplicationSecure extends ApplicationEx implements ProviderInstaller.ProviderInstallListener {
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        Log.i("Security provider check");
+        ProviderInstaller.installIfNeededAsync(this, this);
+    }
+
+    @Override
+    public void onProviderInstalled() {
+        Log.i("Security provider installed");
+    }
+
+    @Override
+    public void onProviderInstallFailed(int errorCode, Intent recoveryIntent) {
+        Log.i("Security provider install failed" +
+                " errorCode=" + errorCode +
+                " recoveryIntent=" + recoveryIntent);
+    }
+}