diff --git a/src/com/android/email/AttachmentInfo.java b/src/com/android/email/AttachmentInfo.java
index 22d632f60..c8d3c307d 100644
--- a/src/com/android/email/AttachmentInfo.java
+++ b/src/com/android/email/AttachmentInfo.java
@@ -151,10 +151,8 @@ public class AttachmentInfo {
         // Check for file size exceeded
         // The size limit is overridden when on a wifi connection - any size is OK
         if (mSize > AttachmentUtilities.MAX_ATTACHMENT_DOWNLOAD_SIZE) {
-            ConnectivityManager cm = (ConnectivityManager)
-                    context.getSystemService(Context.CONNECTIVITY_SERVICE);
-            NetworkInfo network = cm.getActiveNetworkInfo();
-            if (network == null || network.getType() != ConnectivityManager.TYPE_WIFI) {
+            int networkType = EmailConnectivityManager.getActiveNetworkType(context);
+            if (networkType != ConnectivityManager.TYPE_WIFI) {
                 canView = false;
                 canSave = false;
                 denyFlags |= DENY_WIFIONLY;
diff --git a/src/com/android/email/EmailConnectivityManager.java b/src/com/android/email/EmailConnectivityManager.java
index 2e80eac4d..7f549cbb1 100644
--- a/src/com/android/email/EmailConnectivityManager.java
+++ b/src/com/android/email/EmailConnectivityManager.java
@@ -45,6 +45,9 @@ public class EmailConnectivityManager extends BroadcastReceiver {
     // Loop time while waiting (stopgap in case we don't get a broadcast)
     private static final int CONNECTIVITY_WAIT_TIME = 10*60*1000;
 
+    // Sentinel value for "no active network"
+    public static final int NO_ACTIVE_NETWORK = -1;
+
     // The name of this manager (used for logging)
     private final String mName;
     // The monitor lock we use while waiting for connectivity
@@ -151,6 +154,26 @@ public class EmailConnectivityManager extends BroadcastReceiver {
         return (info != null);
     }
 
+    /**
+     * Get the type of the currently active data network
+     * @return the type of the active network (or NO_ACTIVE_NETWORK)
+     */
+    public int getActiveNetworkType() {
+        return getActiveNetworkType(mConnectivityManager);
+    }
+
+    static public int getActiveNetworkType(Context context) {
+        ConnectivityManager cm =
+            (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
+        return getActiveNetworkType(cm);
+    }
+
+    static public int getActiveNetworkType(ConnectivityManager cm) {
+        NetworkInfo info = cm.getActiveNetworkInfo();
+        if (info == null) return NO_ACTIVE_NETWORK;
+        return info.getType();
+    }
+
     public void waitForConnectivity() {
         // If we're unregistered, throw an exception
         if (!mRegistered) {
diff --git a/src/com/android/email/service/AttachmentDownloadService.java b/src/com/android/email/service/AttachmentDownloadService.java
index 3b0ea1739..e52c2da72 100644
--- a/src/com/android/email/service/AttachmentDownloadService.java
+++ b/src/com/android/email/service/AttachmentDownloadService.java
@@ -40,6 +40,7 @@ import android.content.ContentValues;
 import android.content.Context;
 import android.content.Intent;
 import android.database.Cursor;
+import android.net.ConnectivityManager;
 import android.net.Uri;
 import android.os.IBinder;
 import android.os.RemoteException;
@@ -329,6 +330,10 @@ public class AttachmentDownloadService extends Service implements Runnable {
 
             // Don't prefetch if background downloading is disallowed
             if (!mConnectivityManager.isBackgroundDataAllowed()) return;
+            // Don't prefetch unless we're on a WiFi network
+            if (mConnectivityManager.getActiveNetworkType() != ConnectivityManager.TYPE_WIFI) {
+                return;
+            }
             // Then, try opportunistic download of appropriate attachments
             int backgroundDownloads = MAX_SIMULTANEOUS_DOWNLOADS - mDownloadsInProgress.size();
             // Always leave one slot for user requested download