In my network, I have a few end users getting a message that pops up from the system tray saying "Outlook is retrieving data from the Exchange server" and Outlook locks up during that time. Does anyone have any suggestions on what this would be? This started happening 3-4 weeks ago and seems to be random when it happens and doesn't seem to be specific to a certain Windows version or Outlook Version.
Mail Server: 1 2008r2 w/ Exchange 2010
Environment: Windows XP/7 w/ Outlook 2003/2010
DC: 3 Windows Server 2003 w/ replication of AD and DNS