diff --git a/.idea/caches/build_file_checksums.ser b/.idea/caches/build_file_checksums.ser
index e59db92c..c952cd82 100644
Binary files a/.idea/caches/build_file_checksums.ser and b/.idea/caches/build_file_checksums.ser differ
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 6d16400d..e24c4048 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -73,6 +73,11 @@
 
         <service android:name=".ServiceSynchronize" />
 
+        <service
+            android:name=".JobDaily"
+            android:exported="true"
+            android:permission="android.permission.BIND_JOB_SERVICE" />
+
         <provider
             android:name="androidx.core.content.FileProvider"
             android:authorities="${applicationId}"
diff --git a/app/src/main/java/eu/faircode/email/BoundaryCallbackMessages.java b/app/src/main/java/eu/faircode/email/BoundaryCallbackMessages.java
index aff7a1c2..5aa4e6fe 100644
--- a/app/src/main/java/eu/faircode/email/BoundaryCallbackMessages.java
+++ b/app/src/main/java/eu/faircode/email/BoundaryCallbackMessages.java
@@ -1,5 +1,24 @@
 package eu.faircode.email;
 
+/*
+    This file is part of FairEmail.
+
+    FairEmail is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    NetGuard is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with NetGuard.  If not, see <http://www.gnu.org/licenses/>.
+
+    Copyright 2018 by Marcel Bokhorst (M66B)
+*/
+
 import android.content.Context;
 import android.os.Handler;
 import android.util.Log;
@@ -35,7 +54,7 @@ public class BoundaryCallbackMessages extends PagedList.BoundaryCallback<TupleMe
     private String search;
     private Handler mainHandler;
     private IBoundaryCallbackMessages intf;
-    private ExecutorService executor = Executors.newSingleThreadExecutor();
+    private ExecutorService executor = Executors.newSingleThreadExecutor(Helper.backgroundThreadFactory);
 
     private boolean enabled = false;
     private IMAPStore istore = null;
diff --git a/app/src/main/java/eu/faircode/email/DaoLog.java b/app/src/main/java/eu/faircode/email/DaoLog.java
index 7fb9dd72..845da597 100644
--- a/app/src/main/java/eu/faircode/email/DaoLog.java
+++ b/app/src/main/java/eu/faircode/email/DaoLog.java
@@ -40,4 +40,8 @@ public interface DaoLog {
 
     @Insert
     long insertLog(EntityLog log);
+
+    @Query("DELETE FROM log" +
+            " WHERE time < :before")
+    int deleteLogs(long before);
 }
diff --git a/app/src/main/java/eu/faircode/email/FragmentMessage.java b/app/src/main/java/eu/faircode/email/FragmentMessage.java
index eba243e0..99e40ff8 100644
--- a/app/src/main/java/eu/faircode/email/FragmentMessage.java
+++ b/app/src/main/java/eu/faircode/email/FragmentMessage.java
@@ -145,7 +145,7 @@ public class FragmentMessage extends FragmentEx {
     private boolean debug;
     private DateFormat df = SimpleDateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT);
 
-    private ExecutorService executor = Executors.newCachedThreadPool();
+    private ExecutorService executor = Executors.newCachedThreadPool(Helper.backgroundThreadFactory);
 
     private static final long CACHE_IMAGE_DURATION = 3 * 24 * 3600 * 1000L;
     static final String ACTION_DECRYPT_MESSAGE = BuildConfig.APPLICATION_ID + ".DECRYPT_MESSAGE";
diff --git a/app/src/main/java/eu/faircode/email/Helper.java b/app/src/main/java/eu/faircode/email/Helper.java
index 287d742e..07148ac8 100644
--- a/app/src/main/java/eu/faircode/email/Helper.java
+++ b/app/src/main/java/eu/faircode/email/Helper.java
@@ -23,6 +23,7 @@ import android.accounts.Account;
 import android.accounts.AccountManager;
 import android.content.Context;
 import android.content.res.TypedArray;
+import android.support.annotation.NonNull;
 import android.text.TextUtils;
 import android.util.Log;
 import android.view.Menu;
@@ -47,18 +48,32 @@ import java.io.OutputStream;
 import java.io.UnsupportedEncodingException;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
+import java.util.concurrent.ThreadFactory;
 
 import javax.mail.Address;
 import javax.mail.internet.InternetAddress;
 
+import static android.os.Process.THREAD_PRIORITY_BACKGROUND;
+
 public class Helper {
     static final String TAG = "fairemail";
 
+    static final int JOB_DAILY = 1001;
+
     static final int AUTH_TYPE_PASSWORD = 1;
     static final int AUTH_TYPE_GMAIL = 2;
 
     static final int ATTACHMENT_BUFFER_SIZE = 8192; // bytes
 
+    static ThreadFactory backgroundThreadFactory = new ThreadFactory() {
+        @Override
+        public Thread newThread(@NonNull Runnable runnable) {
+            Thread thread = new Thread(runnable);
+            thread.setPriority(THREAD_PRIORITY_BACKGROUND);
+            return thread;
+        }
+    };
+
     static int resolveColor(Context context, int attr) {
         int[] attrs = new int[]{attr};
         TypedArray a = context.getTheme().obtainStyledAttributes(attrs);
diff --git a/app/src/main/java/eu/faircode/email/JobDaily.java b/app/src/main/java/eu/faircode/email/JobDaily.java
new file mode 100644
index 00000000..2cc6f484
--- /dev/null
+++ b/app/src/main/java/eu/faircode/email/JobDaily.java
@@ -0,0 +1,109 @@
+package eu.faircode.email;
+
+/*
+    This file is part of FairEmail.
+
+    FairEmail is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    NetGuard is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with NetGuard.  If not, see <http://www.gnu.org/licenses/>.
+
+    Copyright 2018 by Marcel Bokhorst (M66B)
+*/
+
+import android.app.job.JobInfo;
+import android.app.job.JobParameters;
+import android.app.job.JobScheduler;
+import android.app.job.JobService;
+import android.content.ComponentName;
+import android.content.Context;
+import android.util.Log;
+
+import java.io.File;
+import java.util.Date;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+public class JobDaily extends JobService {
+    private ExecutorService executor = Executors.newSingleThreadExecutor(Helper.backgroundThreadFactory);
+
+    public static void schedule(Context context) {
+        Log.i(Helper.TAG, "Scheduling daily job");
+
+        JobInfo.Builder job = new JobInfo.Builder(Helper.JOB_DAILY, new ComponentName(context, JobDaily.class))
+                .setPeriodic(24 * 3600 * 1000L)
+                .setRequiresDeviceIdle(true);
+
+        JobScheduler scheduler = context.getSystemService(JobScheduler.class);
+        scheduler.cancel(Helper.JOB_DAILY);
+        if (scheduler.schedule(job.build()) == JobScheduler.RESULT_SUCCESS)
+            Log.i(Helper.TAG, "Scheduled daily job");
+        else
+            Log.e(Helper.TAG, "Failed to schedule daily job");
+    }
+
+    @Override
+    public boolean onStartJob(JobParameters args) {
+        Log.i(Helper.TAG, "Starting daily job");
+
+        final DB db = DB.getInstance(this);
+
+        executor.submit(new Runnable() {
+            @Override
+            public void run() {
+                Log.i(Helper.TAG, "Start daily job");
+
+                // Cleanup message files
+                Log.i(Helper.TAG, "Cleanup message files");
+                File[] messages = new File(getFilesDir(), "messages").listFiles();
+                if (messages != null)
+                    for (File file : messages)
+                        if (file.isFile()) {
+                            long id = Long.parseLong(file.getName());
+                            if (db.message().countMessage(id) == 0) {
+                                Log.i(Helper.TAG, "Cleanup message id=" + id);
+                                if (!file.delete())
+                                    Log.w(Helper.TAG, "Error deleting " + file);
+                            }
+                        }
+
+                // Cleanup attachment files
+                Log.i(Helper.TAG, "Cleanup attachment files");
+                File[] attachments = new File(getFilesDir(), "attachments").listFiles();
+                if (attachments != null)
+                    for (File file : attachments)
+                        if (file.isFile()) {
+                            long id = Long.parseLong(file.getName());
+                            if (db.attachment().countAttachment(id) == 0) {
+                                Log.i(Helper.TAG, "Cleanup attachment id=" + id);
+                                if (!file.delete())
+                                    Log.w(Helper.TAG, "Error deleting " + file);
+                            }
+                        }
+
+                Log.i(Helper.TAG, "Cleanup log");
+                long before = new Date().getTime() - 24 * 3600 * 1000L;
+                int logs = db.log().deleteLogs(before);
+                Log.i(Helper.TAG, "Deleted logs=" + logs);
+
+                Log.i(Helper.TAG, "End daily job");
+            }
+        });
+
+        return false;
+    }
+
+    @Override
+    public boolean onStopJob(JobParameters args) {
+        return false;
+    }
+}
+
diff --git a/app/src/main/java/eu/faircode/email/ServiceSynchronize.java b/app/src/main/java/eu/faircode/email/ServiceSynchronize.java
index ebab416a..b6094ac3 100644
--- a/app/src/main/java/eu/faircode/email/ServiceSynchronize.java
+++ b/app/src/main/java/eu/faircode/email/ServiceSynchronize.java
@@ -386,7 +386,7 @@ public class ServiceSynchronize extends LifecycleService {
 
     private void monitorAccount(final EntityAccount account, final ServiceState state) throws NoSuchProviderException {
         final DB db = DB.getInstance(this);
-        final ExecutorService executor = Executors.newSingleThreadExecutor();
+        final ExecutorService executor = Executors.newSingleThreadExecutor(Helper.backgroundThreadFactory);
 
         int backoff = CONNECT_BACKOFF_START;
         while (state.running) {
@@ -1270,28 +1270,6 @@ public class ServiceSynchronize extends LifecycleService {
                     Log.w(Helper.TAG, folder.name + " " + ex + "\n" + Log.getStackTraceString(ex));
                 }
 
-            // Cleanup files
-            File[] messages = new File(getFilesDir(), "messages").listFiles();
-            if (messages != null)
-                for (File file : messages)
-                    if (file.isFile()) {
-                        long id = Long.parseLong(file.getName());
-                        if (db.message().countMessage(id) == 0) {
-                            Log.i(Helper.TAG, "Cleanup message id=" + id);
-                            file.delete();
-                        }
-                    }
-            File[] attachments = new File(getFilesDir(), "attachments").listFiles();
-            if (attachments != null)
-                for (File file : attachments)
-                    if (file.isFile()) {
-                        long id = Long.parseLong(file.getName());
-                        if (db.attachment().countAttachment(id) == 0) {
-                            Log.i(Helper.TAG, "Cleanup attachment id=" + id);
-                            file.delete();
-                        }
-                    }
-
             Log.w(Helper.TAG, folder.name + " statistics added=" + added + " updated=" + updated + " unchanged=" + unchanged);
         } finally {
             Log.v(Helper.TAG, folder.name + " end sync");
@@ -1439,8 +1417,8 @@ public class ServiceSynchronize extends LifecycleService {
         private boolean running = false;
         private Thread main;
         private EntityFolder outbox = null;
-        private ExecutorService lifecycle = Executors.newSingleThreadExecutor();
-        private ExecutorService executor = Executors.newSingleThreadExecutor();
+        private ExecutorService lifecycle = Executors.newSingleThreadExecutor(Helper.backgroundThreadFactory);
+        private ExecutorService executor = Executors.newSingleThreadExecutor(Helper.backgroundThreadFactory);
 
         @Override
         public void onAvailable(Network network) {
@@ -1648,6 +1626,7 @@ public class ServiceSynchronize extends LifecycleService {
 
     public static void start(Context context) {
         ContextCompat.startForegroundService(context, new Intent(context, ServiceSynchronize.class));
+        JobDaily.schedule(context);
     }
 
     public static void reload(Context context, String reason) {
diff --git a/app/src/main/java/eu/faircode/email/SimpleTask.java b/app/src/main/java/eu/faircode/email/SimpleTask.java
index e15c1ca0..11a85015 100644
--- a/app/src/main/java/eu/faircode/email/SimpleTask.java
+++ b/app/src/main/java/eu/faircode/email/SimpleTask.java
@@ -22,12 +22,10 @@ package eu.faircode.email;
 import android.content.Context;
 import android.os.Bundle;
 import android.os.Handler;
-import android.support.annotation.NonNull;
 import android.util.Log;
 
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
-import java.util.concurrent.ThreadFactory;
 
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.fragment.app.Fragment;
@@ -37,8 +35,6 @@ import androidx.lifecycle.LifecycleOwner;
 import androidx.lifecycle.LifecycleService;
 import androidx.lifecycle.OnLifecycleEvent;
 
-import static android.os.Process.THREAD_PRIORITY_BACKGROUND;
-
 //
 // This simple task is simple to use, but it is also simple to cause bugs that can easily lead to crashes
 // Make sure to not access any member in any outer scope from onLoad
@@ -51,14 +47,7 @@ public abstract class SimpleTask<T> implements LifecycleObserver {
     private Bundle args = null;
     private Result stored = null;
 
-    private ExecutorService executor = Executors.newCachedThreadPool(new ThreadFactory() {
-        @Override
-        public Thread newThread(@NonNull Runnable runnable) {
-            Thread thread = new Thread(runnable);
-            thread.setPriority(THREAD_PRIORITY_BACKGROUND);
-            return thread;
-        }
-    });
+    private ExecutorService executor = Executors.newCachedThreadPool(Helper.backgroundThreadFactory);
 
     public void load(Context context, LifecycleOwner owner, Bundle args) {
         run(context, owner, args);