diff --git a/emailcommon/src/com/android/emailcommon/provider/Mailbox.java b/emailcommon/src/com/android/emailcommon/provider/Mailbox.java
index 13b1b5dfa..4a998209b 100644
--- a/emailcommon/src/com/android/emailcommon/provider/Mailbox.java
+++ b/emailcommon/src/com/android/emailcommon/provider/Mailbox.java
@@ -210,6 +210,18 @@ public class Mailbox extends EmailContent implements MailboxColumns, Parcelable
     // A mailbox that holds Messages that are attachments
     public static final int TYPE_ATTACHMENT = 0x101;
 
+    /**
+     * For each of the following folder types, we expect there to be exactly one folder of that
+     * type per account.
+     * Each sync adapter must do the following:
+     * 1) On initial sync: For each type that was not found from the server, create a local folder.
+     * 2) On folder delete: If it's of a required type, convert it to local rather than delete.
+     * 3) On folder add: If it's of a required type, convert the local folder to server.
+     * 4) When adding a duplicate (either initial sync or folder add): Error.
+     */
+    public static final int[] REQUIRED_FOLDER_TYPES =
+            { TYPE_INBOX, TYPE_DRAFTS, TYPE_OUTBOX, TYPE_SENT, TYPE_TRASH };
+
     // Default "touch" time for system mailboxes
     public static final int DRAFTS_DEFAULT_TOUCH_TIME = 2;
     public static final int SENT_DEFAULT_TOUCH_TIME = 1;
diff --git a/src/com/android/email/service/EmailServiceStub.java b/src/com/android/email/service/EmailServiceStub.java
index aef1d8399..6752d8a78 100644
--- a/src/com/android/email/service/EmailServiceStub.java
+++ b/src/com/android/email/service/EmailServiceStub.java
@@ -79,15 +79,6 @@ public abstract class EmailServiceStub extends IEmailService.Stub implements IEm
     private static final int MAILBOX_COLUMN_SERVER_ID = 1;
     private static final int MAILBOX_COLUMN_TYPE = 2;
 
-    /** System folders that should always exist. */
-    private final int[] DEFAULT_FOLDERS = {
-            Mailbox.TYPE_INBOX,
-            Mailbox.TYPE_DRAFTS,
-            Mailbox.TYPE_OUTBOX,
-            Mailbox.TYPE_SENT,
-            Mailbox.TYPE_TRASH
-    };
-
     /** Small projection for just the columns required for a sync. */
     private static final String[] MAILBOX_PROJECTION = new String[] {
         MailboxColumns.ID,
@@ -351,7 +342,7 @@ public abstract class EmailServiceStub extends IEmailService.Stub implements IEm
         Cursor localFolderCursor = null;
         try {
             // Step 0: Make sure the default system mailboxes exist.
-            for (int type : DEFAULT_FOLDERS) {
+            for (final int type : Mailbox.REQUIRED_FOLDER_TYPES) {
                 if (Mailbox.findMailboxOfType(mContext, accountId, type) == Mailbox.NO_MAILBOX) {
                     Mailbox mailbox = Mailbox.newSystemMailbox(mContext, accountId, type);
                     mailbox.save(mContext);