KB Article: http://support.microsoft.com/kb/2009942

INTRODUCTION

When you access a Microsoft Exchange Server 2010 mailbox by using Microsoft Office Outlook 2003 in online mode, you may encounter the following issues:

  • Outgoing email messages stay in the Outbox folder for up to 1 minute.
  • New email messages do not arrive in the Inbox folder immediately and are delayed for up to 1 minute.
  • Items that are deleted from folders still appear in the folder for up to 1 minute.
  • Items that are moved from one folder to another folder still appear in the original folder for up to 1 minute.

The folder updates do not occur in a timely manner.