diff --git a/src/com/fsck/k9/activity/Accounts.java b/src/com/fsck/k9/activity/Accounts.java
index 5331890d6..738ee32a3 100644
--- a/src/com/fsck/k9/activity/Accounts.java
+++ b/src/com/fsck/k9/activity/Accounts.java
@@ -117,7 +117,10 @@ public class Accounts extends K9ListActivity implements OnItemClickListener {
     private static final int DIALOG_RECREATE_ACCOUNT = 3;
     private static final int DIALOG_NO_FILE_MANAGER = 4;
 
-    private ConcurrentMap<String, AccountStats> accountStats = new ConcurrentHashMap<String, AccountStats>();
+    /*
+     * Must be serializable hence implementation class used for declaration.
+     */
+    private ConcurrentHashMap<String, AccountStats> accountStats = new ConcurrentHashMap<String, AccountStats>();
 
     private ConcurrentMap<BaseAccount, String> pendingWork = new ConcurrentHashMap<BaseAccount, String>();
 
@@ -492,7 +495,7 @@ public class Accounts extends K9ListActivity implements OnItemClickListener {
             outState.putString(SELECTED_CONTEXT_ACCOUNT, mSelectedContextAccount.getUuid());
         }
         outState.putSerializable(STATE_UNREAD_COUNT, mUnreadMessageCount);
-        outState.putSerializable(ACCOUNT_STATS, Utility.toSerializableConcurrentMap(accountStats));
+        outState.putSerializable(ACCOUNT_STATS, accountStats);
     }
 
     private StorageManager.StorageListener storageListener = new StorageManager.StorageListener() {
diff --git a/src/com/fsck/k9/activity/MessageCompose.java b/src/com/fsck/k9/activity/MessageCompose.java
index 8110f66e9..5b975247c 100644
--- a/src/com/fsck/k9/activity/MessageCompose.java
+++ b/src/com/fsck/k9/activity/MessageCompose.java
@@ -1154,7 +1154,7 @@ public class MessageCompose extends K9Activity implements OnClickListener,
     @Override
     protected void onSaveInstanceState(Bundle outState) {
         super.onSaveInstanceState(outState);
-        List<Attachment> attachments = new ArrayList<Attachment>();
+        ArrayList<Attachment> attachments = new ArrayList<Attachment>();
         for (int i = 0, count = mAttachments.getChildCount(); i < count; i++) {
             View view = mAttachments.getChildAt(i);
             Attachment attachment = (Attachment) view.getTag();
@@ -1163,7 +1163,7 @@ public class MessageCompose extends K9Activity implements OnClickListener,
 
         outState.putInt(STATE_KEY_NUM_ATTACHMENTS_LOADING, mNumAttachmentsLoading);
         outState.putString(STATE_KEY_WAITING_FOR_ATTACHMENTS, mWaitingForAttachments.name());
-        outState.putParcelableArrayList(STATE_KEY_ATTACHMENTS, Utility.toArrayList(attachments));
+        outState.putParcelableArrayList(STATE_KEY_ATTACHMENTS, attachments);
         outState.putBoolean(STATE_KEY_CC_SHOWN, mCcWrapper.getVisibility() == View.VISIBLE);
         outState.putBoolean(STATE_KEY_BCC_SHOWN, mBccWrapper.getVisibility() == View.VISIBLE);
         outState.putSerializable(STATE_KEY_QUOTED_TEXT_MODE, mQuotedTextMode);
diff --git a/src/com/fsck/k9/activity/NotificationDeleteConfirmation.java b/src/com/fsck/k9/activity/NotificationDeleteConfirmation.java
index 9a070ed39..fd6f87db5 100644
--- a/src/com/fsck/k9/activity/NotificationDeleteConfirmation.java
+++ b/src/com/fsck/k9/activity/NotificationDeleteConfirmation.java
@@ -1,5 +1,6 @@
 package com.fsck.k9.activity;
 
+import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -25,12 +26,12 @@ public class NotificationDeleteConfirmation extends Activity {
     private final static int DIALOG_CONFIRM = 1;
 
     private Account mAccount;
-    private List<MessageReference> mMessageRefs;
+    private ArrayList<MessageReference> mMessageRefs;
 
-    public static PendingIntent getIntent(Context context, final Account account, final List<MessageReference> refs) {
+    public static PendingIntent getIntent(Context context, final Account account, final Serializable refs) {
         Intent i = new Intent(context, NotificationDeleteConfirmation.class);
         i.putExtra(EXTRA_ACCOUNT, account.getUuid());
-        i.putExtra(EXTRA_MESSAGE_LIST, Utility.toSerializableList(refs));
+        i.putExtra(EXTRA_MESSAGE_LIST, refs);
         i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TOP);
 
         return PendingIntent.getActivity(context, account.getAccountNumber(), i, PendingIntent.FLAG_UPDATE_CURRENT);
diff --git a/src/com/fsck/k9/controller/MessagingController.java b/src/com/fsck/k9/controller/MessagingController.java
index e09453e9b..07f2f5e05 100644
--- a/src/com/fsck/k9/controller/MessagingController.java
+++ b/src/com/fsck/k9/controller/MessagingController.java
@@ -2,6 +2,7 @@ package com.fsck.k9.controller;
 
 import java.io.CharArrayWriter;
 import java.io.PrintWriter;
+import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -286,17 +287,14 @@ public class MessagingController implements Runnable {
         }
 
         /**
-         * Gets a list of references for all pending messages for the notification.
-         *
-         * @return Message reference list
+         * Adds a list of references for all pending messages for the notification to the supplied
+         * List.
          */
-        public List<MessageReference> getAllMessageRefs() {
-            List<MessageReference> refs = new ArrayList<MessageReference>();
+        public void supplyAllMessageRefs(List<MessageReference> refs) {
             for (Message m : messages) {
                 refs.add(m.makeMessageReference());
             }
             refs.addAll(droppedMessages);
-            return refs;
         }
 
         /**
@@ -4844,7 +4842,8 @@ public class MessagingController implements Runnable {
 
         String accountDescr = (account.getDescription() != null) ?
                 account.getDescription() : account.getEmail();
-        final List<MessageReference> allRefs = data.getAllMessageRefs();
+        final ArrayList<MessageReference> allRefs = new ArrayList<MessageReference>();
+        data.supplyAllMessageRefs(allRefs);
 
         if (platformSupportsExtendedNotifications() && !privacyModeEnabled) {
             if (newMessages > 1) {
diff --git a/src/com/fsck/k9/helper/Utility.java b/src/com/fsck/k9/helper/Utility.java
index a03a774fb..370920d59 100644
--- a/src/com/fsck/k9/helper/Utility.java
+++ b/src/com/fsck/k9/helper/Utility.java
@@ -724,22 +724,4 @@ public class Utility {
         return sMainThreadHandler;
     }
 
-    public static <T> Serializable toSerializableList(List<T> list) {
-        return list instanceof Serializable ?
-                (Serializable) list :
-                new ArrayList<T>(list);
-    }
-
-    public static <T> ArrayList<T> toArrayList(List<T> list) {
-        return list instanceof ArrayList ?
-                (ArrayList<T>) list :
-                new ArrayList<T>(list);
-    }
-
-
-    public static <T,U> Serializable toSerializableConcurrentMap(ConcurrentMap<T,U> list) {
-        return list instanceof ConcurrentHashMap ?
-                (ConcurrentHashMap<T,U>) list :
-                new ConcurrentHashMap<T,U>(list);
-    }
 }
diff --git a/src/com/fsck/k9/service/NotificationActionService.java b/src/com/fsck/k9/service/NotificationActionService.java
index e4cad21c9..107bd0f4c 100644
--- a/src/com/fsck/k9/service/NotificationActionService.java
+++ b/src/com/fsck/k9/service/NotificationActionService.java
@@ -1,5 +1,6 @@
 package com.fsck.k9.service;
 
+import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -37,11 +38,10 @@ public class NotificationActionService extends CoreService {
         return PendingIntent.getService(context, account.getAccountNumber(), i, PendingIntent.FLAG_UPDATE_CURRENT);
     }
 
-    public static PendingIntent getReadAllMessagesIntent(Context context, final Account account,
-            final List<MessageReference> refs) {
+    public static PendingIntent getReadAllMessagesIntent(Context context, final Account account, final Serializable refs) {
         Intent i = new Intent(context, NotificationActionService.class);
         i.putExtra(EXTRA_ACCOUNT, account.getUuid());
-        i.putExtra(EXTRA_MESSAGE_LIST, Utility.toSerializableList(refs));
+        i.putExtra(EXTRA_MESSAGE_LIST, refs);
         i.setAction(READ_ALL_ACTION);
 
         return PendingIntent.getService(context, account.getAccountNumber(), i, PendingIntent.FLAG_UPDATE_CURRENT);
@@ -55,11 +55,10 @@ public class NotificationActionService extends CoreService {
         return PendingIntent.getService(context, account.getAccountNumber(), i, PendingIntent.FLAG_UPDATE_CURRENT);
     }
 
-    public static Intent getDeleteAllMessagesIntent(Context context, final Account account,
-            final List<MessageReference> refs) {
+    public static Intent getDeleteAllMessagesIntent(Context context, final Account account, final Serializable refs) {
         Intent i = new Intent(context, NotificationActionService.class);
         i.putExtra(EXTRA_ACCOUNT, account.getUuid());
-        i.putExtra(EXTRA_MESSAGE_LIST, Utility.toSerializableList(refs));
+        i.putExtra(EXTRA_MESSAGE_LIST, refs);
         i.setAction(DELETE_ALL_ACTION);
 
         return i;