diff --git a/src/com/android/phone/vvm/omtp/OmtpVvmSyncAccountManager.java b/src/com/android/phone/vvm/omtp/OmtpVvmSyncAccountManager.java
index a4cf4e8..b891c70 100644
--- a/src/com/android/phone/vvm/omtp/OmtpVvmSyncAccountManager.java
+++ b/src/com/android/phone/vvm/omtp/OmtpVvmSyncAccountManager.java
@@ -25,6 +25,7 @@
 import android.util.Log;
 
 import com.android.phone.PhoneUtils;
+import com.android.phone.vvm.omtp.sms.StatusMessage;
 
 /**
  * A singleton class designed to assist in OMTP visual voicemail sync behavior.
@@ -118,4 +119,20 @@
         }
         return false;
     }
+
+    /**
+     * Set the IMAP credentials as extra fields in the account.
+     *
+     * @param account The account to add credentials to.
+     * @param message The status message to extract the fields from.
+     */
+    public void setAccountCredentialsFromStatusMessage(Account account, StatusMessage message) {
+        mAccountManager.setUserData(account, OmtpConstants.IMAP_PORT, message.getImapPort());
+        mAccountManager.setUserData(account, OmtpConstants.SERVER_ADDRESS,
+                message.getServerAddress());
+        mAccountManager.setUserData(account, OmtpConstants.IMAP_USER_NAME,
+                message.getImapUserName());
+        mAccountManager.setUserData(account, OmtpConstants.IMAP_PASSWORD,
+                message.getImapPassword());
+    }
 }
diff --git a/src/com/android/phone/vvm/omtp/OmtpVvmSyncService.java b/src/com/android/phone/vvm/omtp/OmtpVvmSyncService.java
index 811e7e6..471baab 100644
--- a/src/com/android/phone/vvm/omtp/OmtpVvmSyncService.java
+++ b/src/com/android/phone/vvm/omtp/OmtpVvmSyncService.java
@@ -25,11 +25,19 @@
 import android.app.Service;
 import android.content.AbstractThreadedSyncAdapter;
 import android.content.ContentProviderClient;
+import android.content.ContentResolver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SyncResult;
+import android.database.Cursor;
 import android.os.Bundle;
 import android.os.IBinder;
+import android.telecom.Voicemail;
+
+import com.android.phone.vvm.omtp.sync.DirtyVoicemailQuery;
+
+import java.util.ArrayList;
+import java.util.List;
 
 /**
  * A service to run the VvmSyncAdapter.
@@ -40,6 +48,8 @@
     // Object to use as a thread-safe lock
     private static final Object sSyncAdapterLock = new Object();
 
+    private Context mContext;
+
     @Override
     public void onCreate() {
         synchronized (sSyncAdapterLock) {
@@ -57,12 +67,40 @@
     public class OmtpVvmSyncAdapter extends AbstractThreadedSyncAdapter {
         public OmtpVvmSyncAdapter(Context context, boolean autoInitialize) {
             super(context, autoInitialize);
+            mContext = context;
         }
 
         @Override
         public void onPerformSync(Account account, Bundle extras, String authority,
                 ContentProviderClient provider, SyncResult syncResult) {
-            // TODO: Write code necessary for syncing.
+            if (extras.getBoolean(ContentResolver.SYNC_EXTRAS_UPLOAD, false)) {
+                List<Voicemail> readVoicemails = new ArrayList<Voicemail>();
+                List<Voicemail> deletedVoicemails = new ArrayList<Voicemail>();
+
+                Cursor cursor = DirtyVoicemailQuery.getDirtyVoicemails(mContext);
+                if (cursor == null) {
+                    return;
+                }
+                try {
+                    while (cursor.moveToNext()) {
+                        final long id = cursor.getLong(DirtyVoicemailQuery._ID);
+                        final String sourceData = cursor.getString(DirtyVoicemailQuery.SOURCE_DATA);
+                        final boolean isRead = cursor.getInt(DirtyVoicemailQuery.IS_READ) == 1;
+                        final boolean deleted = cursor.getInt(DirtyVoicemailQuery.DELETED) == 1;
+                        Voicemail voicemail = Voicemail.createForUpdate(id, sourceData).build();
+                        if (deleted) {
+                            // Check deleted first because if the voicemail is deleted, there's no
+                            // need to mark as read.
+                            deletedVoicemails.add(voicemail);
+                        } else if (isRead) {
+                            readVoicemails.add(voicemail);
+                        }
+                    }
+                } finally {
+                    cursor.close();
+                }
+                //TODO: send to server via IMAP
+            }
         }
     }
 }
diff --git a/src/com/android/phone/vvm/omtp/sms/OmtpMessageReceiver.java b/src/com/android/phone/vvm/omtp/sms/OmtpMessageReceiver.java
index c00441a..9181e50 100644
--- a/src/com/android/phone/vvm/omtp/sms/OmtpMessageReceiver.java
+++ b/src/com/android/phone/vvm/omtp/sms/OmtpMessageReceiver.java
@@ -24,6 +24,7 @@
 import android.provider.Telephony;
 import android.provider.VoicemailContract;
 import android.telecom.PhoneAccountHandle;
+import android.telecom.Voicemail;
 import android.telephony.SmsMessage;
 import android.util.Log;
 
@@ -62,10 +63,10 @@
         if (messageData != null) {
             if (messageData.getPrefix() == OmtpConstants.SYNC_SMS_PREFIX) {
                 SyncMessage message = new SyncMessage(messageData);
-                //TODO: handle message
+                processSync(message);
             } else if (messageData.getPrefix() == OmtpConstants.STATUS_SMS_PREFIX) {
                 StatusMessage message = new StatusMessage(messageData);
-                handleStatusMessage(message);
+                updateAccount(message);
             } else {
                 Log.e(TAG, "This should never have happened");
             }
@@ -83,20 +84,61 @@
         }
     }
 
-    private void handleStatusMessage(StatusMessage message) {
-        OmtpVvmSyncAccountManager vvmSyncManager = OmtpVvmSyncAccountManager.getInstance(mContext);
+    /**
+     * A sync message has two purposes: to signal a new voicemail message, and to indicate the
+     * voicemails on the server have changed remotely (usually through the TUI). Save the new
+     * message to the voicemail provider if it is the former case and perform a full sync in the
+     * latter case.
+     *
+     * @param message The sync message to extract data from.
+     */
+    private void processSync(SyncMessage message) {
+        switch (message.getSyncTriggerEvent()) {
+            case OmtpConstants.NEW_MESSAGE:
+                Voicemail voicemail = Voicemail.createForInsertion(
+                        message.getTimestampMillis(), message.getSender())
+                        .setSourceData(message.getId())
+                        .setDuration(message.getLength())
+                        .setSourcePackage(mContext.getPackageName())
+                        .build();
+
+                VoicemailContract.Voicemails.insert(mContext, voicemail);
+                break;
+            case OmtpConstants.MAILBOX_UPDATE:
+                // Needs a total resync
+                ContentResolver.requestSync(
+                        new Account(mPhoneAccount.getId(), OmtpVvmSyncAccountManager.ACCOUNT_TYPE),
+                        VoicemailContract.AUTHORITY, new Bundle());
+                break;
+            case OmtpConstants.GREETINGS_UPDATE:
+                // Not implemented in V1
+                break;
+           default:
+               Log.e(TAG, "Unrecognized sync trigger event: "+message.getSyncTriggerEvent());
+               break;
+        }
+    }
+
+    private void updateAccount(StatusMessage message) {
+        OmtpVvmSyncAccountManager vvmAccountSyncManager =
+                OmtpVvmSyncAccountManager.getInstance(mContext);
         Account account = new Account(mPhoneAccount.getId(),
                 OmtpVvmSyncAccountManager.ACCOUNT_TYPE);
 
-        if (!vvmSyncManager.isAccountRegistered(account)) {
+        if (!vvmAccountSyncManager.isAccountRegistered(account)) {
             // If the account has not been previously registered, it means that this STATUS sms
             // is a result of the ACTIVATE sms, so register the voicemail source.
-            vvmSyncManager.createSyncAccount(account);
+            vvmAccountSyncManager.createSyncAccount(account);
             VoicemailContract.Status.setStatus(mContext, mPhoneAccount,
                     VoicemailContract.Status.CONFIGURATION_STATE_OK,
                     VoicemailContract.Status.DATA_CHANNEL_STATE_OK,
                     VoicemailContract.Status.NOTIFICATION_CHANNEL_STATE_OK);
         }
+
+        // Save the IMAP credentials in the corresponding account object so they are
+        // persistent and can be retrieved.
+        vvmAccountSyncManager.setAccountCredentialsFromStatusMessage(account, message);
+
         ContentResolver.requestSync(account, VoicemailContract.AUTHORITY, new Bundle());
     }
 }
diff --git a/src/com/android/phone/vvm/omtp/sync/DirtyVoicemailQuery.java b/src/com/android/phone/vvm/omtp/sync/DirtyVoicemailQuery.java
new file mode 100644
index 0000000..965b36b
--- /dev/null
+++ b/src/com/android/phone/vvm/omtp/sync/DirtyVoicemailQuery.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+package com.android.phone.vvm.omtp.sync;
+
+import android.content.ContentResolver;
+import android.content.Context;
+import android.database.Cursor;
+import android.net.Uri;
+import android.provider.VoicemailContract;
+import android.provider.VoicemailContract.Voicemails;
+
+/**
+ * Construct a query to get dirty voicemails.
+ */
+public class DirtyVoicemailQuery {
+    final static String[] PROJECTION = new String[] {
+            Voicemails._ID,              // 0
+            Voicemails.SOURCE_DATA,      // 1
+            Voicemails.IS_READ,          // 2
+            Voicemails.DELETED,          // 3
+    };
+
+    public static final int _ID = 0;
+    public static final int SOURCE_DATA = 1;
+    public static final int IS_READ = 2;
+    public static final int DELETED = 3;
+
+    final static String SELECTION = Voicemails.DIRTY + "=1";
+
+    /**
+     * Get all the locally modified voicemails that have not been synced to the server.
+     *
+     * @param context The context from the package calling the method. This will be the source.
+     * @return A list of all locally modified voicemails.
+     */
+    public static Cursor getDirtyVoicemails(Context context) {
+        ContentResolver contentResolver = context.getContentResolver();
+        Uri statusUri = VoicemailContract.Voicemails.buildSourceUri(context.getPackageName());
+        return contentResolver.query(statusUri, PROJECTION, SELECTION, null, null);
+    }
+}